Environmentally friendly coating compositions for coating metal objects, coated objects therefrom and methods, processes and assemblages for coating thereof

ABSTRACT

Disclosed are environmentally friendly, substantially all solids coating compositions which are curable using ultraviolet and visible radiation. In certain embodiments, the disclosed coating compositions are suitable for coating flexible objects and/or objects having angular features, such as, but not limited to, flexible metal objects with angular features. In other embodiments, the cured coatings have improved slip properties and at least 6 H hardness. Such embodiments can served as substitutes for &#34;hard chrome&#34; coatings, TEFLON(R) coatings, coatings comprising TEFLON(R), or TEFLON(R) like coatings. In addition, methods are disclosed for coating surfaces, or at least a portion of the surfaces, and curing of the coated surface to obtain partially or fully cured coated surfaces. Furthermore, articles of manufacture incorporating fully cured coated surfaces are disclosed, including, for example leaf springs, hydraulic rods and cylinders. Also disclosed are methods, processes, production lines, articles of manufacture, and factories which incorporate these environmentally friendly, substantially all solids coating compositions curable using ultraviolet and visible radiation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/075,647, filed on Mar. 8, 2005, now U.S. Pat. No. 7,238,731,which claims benefit to U.S. Provisional Application No. 60/551,287,filed on Mar. 8, 2004, 60/556,221, filed on Mar. 25, 2004 and60/557,074, filed on Mar. 26, 2004; and is also a continuation-in-partof U.S. patent application Ser. Nos. 10/983,022, filed on Nov. 5, 2004,now U.S. Pat. No. 7,151,123, Ser. No. 10/982,998, filed on Nov. 5, 2004,and Ser. No. 11/003,159, filed on Dec. 2, 2004, now U.S. Pat. No.7,192,992; the present Application also claims benefit of U.S.Provisional Application 60/637,028, filed on Dec. 17, 2004; thedisclosures of all which are hereby incorporated by references in theirentirety.

BACKGROUND OF THE INVENTION

A variety of consumer, scientific, and industrial products incorporatevarious metals in a variety of forms and shapes. Coating such metalsurfaces with solvent based coating can be problematic due toenvironmental issues stemming from evaporation of the volatile solvent.Also, such coatings can require thermal curing, resulting in the needfor curing ovens, and the associated energy expenditure to operate them.Such consumer, scientific, and industrial products may have functionswhich require the product to be hard, slippery (i.e., possessing a lowcoefficient of friction), or both hard and slippery. Products which arehard and abrasion resistant, with good slip properties are desired, asthis may increase the products lifetime. By way of example, suchproducts may include hydraulic rods and hydraulic cylinders, pneumaticstruts, shock absorbers, ball joints, axels, and wheel bearings andcouplers. “Hard chrome” coatings have been used to impart hardness toproducts; however separate coatings are needed to impart good slipproperties to these hard coated products, for example TEFLON® typecoatings. Furthermore, chrome coating processes are inherently notenvironmentally friendly, as they have both environmental and healthissues.

SUMMARY OF THE INVENTION

Presented herein are environmentally friendly actinic radiation curable,substantially all solids compositions and methods for coating metalobjects or plastic objects. Also presented herein are environmentallyfriendly actinic radiation curable, substantially all solidscompositions and methods to obtain flexible, and/or abrasion and scratchresistant, and/or impact resistant and/or smooth, and/or hard coatings,which also exhibits enhanced adhesion and/or slip properties. Alsopresented herein are environmentally friendly actinic radiation curable,substantially all solids compositions and methods for coating flexibleobjects, such as, by way of example only, flexible metal or plasticobjects. Further presented herein are environmentally friendly actinicradiation curable, substantially all solids compositions and methods forcoating object with angular features such as, by way of example only,metal or plastic objects with angular features. Further presented hereinare environmentally friendly actinic radiation curable, substantiallyall solids compositions and methods for coating object that produce acoating, upon curing, that has improved properties, including by way ofexample, improved tensile strength, improved resistance to damagefollowing elongation of the coated object, improved resistance to damagefollowing bending the coating object, improved resistance to damagefollowing cupping of the coated object, or a combination of any of theaforementioned improved properties. Such coating compositions produceless volatile materials, produce less waste and require less energy.Furthermore, such coating compositions may be used to produce coatingshaving desirable esthetic, performance and durability properties.Further presented are partially and fully cured surfaces, along witharticles of manufacture incorporating fully cured surfaces.

In one aspect the actinic radiation curable, substantially all solidscompositions described herein are comprised of a mixture of at least oneoligomer, at least one monomer, at least one photoinitiator, and atleast one nano-filler, wherein the cured composition exhibits 99+%adhesion after 10 days at 110° F. in 100% humidity, and/or a 180 degreebend around a mandrel, such as, by way of example only, a half inchmandrel. In a further embodiment, the cured composition is a coating ona metal or plastic object. In a further embodiment, the curedcomposition can provide a flexible, corrosion resistant, abrasionresistant and scratch resistant coating on a metal or plastic object.

In an embodiment of the aforementioned aspect, the actinic radiationcurable, substantially all solids composition comprises at least oneoligomer or a multiplicity of oligomers present in the mixture betweenabout 15-45% by weight. In a further or alternative embodiments of theabove aspect, the actinic radiation curable, substantially all solidscomposition comprises at least one monomer or a multiplicity of monomerspresent in the mixture between about 25-65% by weight. In further oralternative embodiments, the actinic radiation curable, substantiallyall solids composition comprises at least one photoinitiator or amultiplicity of photoinitiators present in the mixture between about2-10% by weight. In a still further or alternate embodiment, the actinicradiation curable, substantially all solids composition comprises atleast one nano-filler or a multiplicity of nano-fillers present in themixture between about 0.1-25% by weight. In further or alternativeembodiments of the aforementioned aspect, the actinic radiation curable,substantially all solids composition optionally comprises up to about 5%by weight of a filler or a multiplicity of fillers. In further oralternative embodiments of the aforementioned aspect, the actinicradiation curable, substantially all solids composition optionallycomprises up to about 10% by weight of a polymerizable pigmentdispersion or a multiplicity of polymerizable pigment dispersions. Instill further or alternative embodiments of the aforementioned aspect,the actinic radiation curable, substantially all solids compositionmixture comprises 15-45% percent by weight of an oligomer or amultiplicity of oligomers, and 25-65% by weight of a monomer or amultiplicity of monomers. In further or alternative embodiments of thisaspect, the actinic radiation curable, substantially all solidscomposition comprises 15-45% percent by weight of an oligomer or amultiplicity of oligomers, 25-65% by weight a monomer or a multiplicityof monomers and 2-10% by weight of a photoinitiator or a multiplicity ofphotoinitiators. In still further or alternative embodiments, theactinic radiation curable, substantially all solids compositioncomprises 15-45% percent by weight of an oligomer or a multiplicity ofoligomers, 25-65% by weight of a monomer or a multiplicity of monomers,2-10% by weight of a photoinitiator or a multiplicity ofphotoinitiators, and 0.1-25% by weight of a nano-filler or amultiplicity of nano-fillers. In further or alternative embodiments, theactinic radiation curable, substantially all solids comprises 15-45%percent by weight an oligomer or a multiplicity of oligomers, 25-65% byweight of a monomer or a multiplicity of monomers, 2-10% by weight of aphotoinitiator or a multiplicity of photoinitiators, 0.1-25% by weightof a nano-filler or a multiplicity of nano-fillers, and up to about 5%by weight of a filler or a multiplicity of fillers. In even further oralternative embodiments, the actinic radiation curable, substantiallyall solids composition comprises 15-45% percent by weight an oligomer ora multiplicity of oligomers, 30-65% by weight of a monomer or amultiplicity of monomers, 2-10% by weight of a photoinitiator or amultiplicity of photoinitiators, 0.1-5% by weight of a nano-filler or amultiplicity of nano-fillers, up to about 5% by weight of a filler or amultiplicity of fillers, and up to about 10% by weight of apolymerizable pigment dispersion or a multiplicity of polymerizablepigment dispersions; whereby the room temperature viscosity of thecomposition is up to about 500 centipoise.

In further or alternative embodiments of this aspect, the oligomers maybe selected from a group consisting of urethane acrylates, aliphaticurethane acrylates, aliphatic urethane triacrylate/monomer blends,aliphatic urethane triacrylates blended with 1,6-hexanediol acrylates,hexafunctional urethane acrylates, siliconized urethane acrylates,aliphatic siliconized urethane acrylates, polyether acrylates, andcombinations thereof. In another or alternative embodiments the monomersare selected from a group consisting of trimethylolpropane triacrylates,2-phenoxyethyl acrylates, isobornyl acrylates, propoxylated glyceryltriacrylates, acrylate ester derivatives, methacrylate esterderivatives, acrylate ester derivatives, tripropylene glycol diacrylate,and combinations thereof.

In still further or alternative embodiments, the photoinitiators may beselected from a group consisting of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, benzophenone, ESACURE® KTO,IRGACURE® 500, DARACUR® 1173, Lucirin® TPO, 1-hydroxycyclohexyl phenylketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one,2,4,6,-trimethylbenzophenone, 4-methylbenzophenone,oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone), andcombinations thereof. In another or alternative embodiments, the actinicradiation curable, substantially all solids composition furthercomprises up to about 2% of a co-photoinitiator selected from amineacrylates, thioxanthone, dimethyl ketal, benzyl methyl ketal, andcombinations thereof.

In a still further or alternative embodiment, the fillers are selectedfrom a group consisting of amorphous silicon dioxide prepared withpolyethylene wax, synthetic amorphous silica with organic surfacetreatment, IRGANOX®, untreated amorphous silicon dioxide, alkylquaternary bentonite, colloidal silica, acrylated colloidal silica,alumina, zirconia, zinc oxide, niobia, titania aluminum nitride, silveroxide, cerium oxides, and combinations thereof. Further, the averagesize of the filler particles is less than 10 micrometers, or less than 5micrometers, or even less than 1 micrometer.

In further or alternative embodiments of the aforementioned aspect, thenano-fillers may be selected from a group consisting of nano-aluminumoxide, nano-silicon dioxide, nano-zirconium oxide, nano-zirconiumdioxides, nano-silicon carbide, nano-silicon nitride, nano-sialon,nano-aluminum nitride, nano-bismuth oxide, nano-cerium oxide,nano-copper oxide, nano-iron oxide, nano-nickel titanate, nano-niobiumoxide, nano-rare earth oxide, nano-silver oxide, nano-tin oxide, andnano-titanium oxide, and combinations thereof. In addition, the averagesize of the nano-filler particles is less than 100 nanometers.

In further or alternative embodiments, the polymerizable pigmentdispersions are comprised of at least one pigment attached to anactivated resin; wherein the activated resin is selected from a groupconsisting of acrylate resins, methacrylate resins, and vinyl resins,and the pigment is selected from a group consisting of carbon black,rutile titanium dioxide, organic red pigment, phthalo blue pigment, redoxide pigment, isoindoline yellow pigment, phthalo green pigment,quinacridone violet, carbazole violet, masstone black, light lemonyellow oxide, light organic yellow, transparent yellow oxide, diarylideorange, quinacridone red, organic scarlet, light organic red, and deeporganic red.

In further or alternative embodiments, the actinic radiation curable,substantially all solids composition is suitable for coating flexibleobjects, such as, by way of example only, metal or plastic objects. Infurther or alternative embodiments, the actinic radiation curable,substantially all solids composition is suitable for coating objectscomprising angular features.

In further or alternative embodiments, the actinic radiation curable,substantially all solids composition is suitable as an uncured coatingon flexible objects, such as, by way of example only, metal or plasticobjects. In still further or alternative embodiment, the actinicradiation curable, substantially all solids composition is suitable asan uncured coating on objects comprising angular features.

In further or alternative embodiments, the coating may be applied to thesurface of flexible objects, such as, by way of example only, metal orplastic objects, by means of spraying, brushing, rolling, dipping, bladecoating, curtain coating or a combination thereof. Further, the means ofspraying includes, but is not limited to, the use of a High Volume LowPressure (HVLP) spraying systems, air-assisted/airless spraying systems,or electrostatic spraying systems. In further or alternativeembodiments, the coating is applied in a single application, or inmultiple applications. In further or alternative embodiments, thesurfaces of flexible objects, such as, by way of example only, metal orplastic objects, are partially covered by the uncured coating, or in astill further or alternative embodiments, the surfaces of flexibleobjects, such as, by way of example only, metal or plastic objects, arefully covered by the uncured coating.

In further or alternative embodiments, the coating may be applied to thesurface of objects comprising angular features by means of spraying,brushing, rolling, dipping, blade coating, curtain coating or acombination thereof. Further, the means of spraying includes, but is notlimited to, the use of a High Volume Low Pressure (HVLP) sprayingsystems, air-assisted/airless spraying systems, or electrostaticspraying systems. In further or alternative embodiments, the coating isapplied in a single application, or in multiple applications. In furtheror alternative embodiments, the surfaces of objects comprising angularfeatures are partially covered by the uncured coating, or in stillfurther or alternative embodiments, the surfaces of objects comprisingangular features are fully covered by the uncured coating. In further oralternative embodiments, the objects comprising angular features areflexible, and in still further or alternative embodiments, the objectscomprising angular features comprise metal, ceramic, glass, wood, and/orplastic.

In further or alternative embodiments, the coated surfaces of flexibleobjects, such as, by way of example only, metal or plastic objects, arepartially cured by exposure of uncured coated surfaces to a first sourceof actinic radiation. In further or alternative embodiments, the coatedsurfaces of flexible objects, such as, by way of example only, metal orplastic objects, are fully cured by exposure of the partially curedcoated surface to a second source of actinic radiation. In further oralternative embodiments, the coated surfaces of objects comprisingangular features are partially cured by exposure of uncured coatedsurfaces to a first source of actinic radiation. In further oralternative embodiments, the coated surfaces of objects comprisingangular features are fully cured by exposure of the partially curedcoated surface to a second source of actinic radiation.

In further or alternative embodiments, the fully cured coatings areflexible, adherent, hard, glossy, corrosion resistant, abrasionresistant, scratch resistant, or any combinations thereof.

In further or alternative embodiments, the actinic radiation is selectedfrom the group consisting of visible radiation, near visible radiation,ultra-violet (UV) radiation, and combinations thereof. Further, the UVradiation is selected from the group consisting of UV-A radiation, UV-Bradiation, UV-B radiation, UV-C radiation, UV-D radiation, orcombinations thereof.

In further or alternative embodiments, the completely cured coatedsurface is part of articles of manufacture. In further or alternativeembodiments, the articles of manufacture include the completely curedcoated surface. In further or alternative embodiments, the article ofmanufacture coated may be an article of manufacture wherein at least oneof its functions would be enhanced or improved by the presence of acoating which is flexible, adherent, hard, glossy, corrosion resistant,abrasion resistant, scratch resistant, or any combinations thereof. Infurther or alternative embodiments, the articles of manufacture are leafsprings or the undercarriage of automobiles.

In a further aspect the method for producing the actinic radiationcurable, substantially all solids composition involves adding thecomponents, for instance, by way of example only, least one oligomer, atleast one monomer, at least one photoinitiator, optionally at least oneco-photoinitiator, at least one nano-filler, optionally at least onefiller, and optionally at least one polymerizable pigment dispersion,and using a means for mixing the components together to form a smoothcomposition. In further or alternative embodiments, the composition maybe mixed in or transferred to a suitable container, such as, but notlimited to, a can.

In another aspect are assemblages for coating at least a portion of asurface of flexible objects (by way of example only, metal or plasticobjects), or objects comprising angular features, with an actinicradiation curable, substantially all solids composition comprising ameans for applying to the object an actinic radiation curable,substantially all solids composition; a means for irradiating theapplied coating with a first actinic radiation so as to partially curethe applied coating on the surface; and a means for irradiating theobject with a second actinic radiation so as to completely cure thepartially cured coating on the surface, wherein the cured composition isa flexible, corrosion resistant, abrasion resistant and scratchresistant coating with 99+% adhesion after 10 days at 110 F in 100%humidity, and/or a 180 degree bend around a mandrel, such as, by way ofexample only, a half inch mandrel.

In one embodiment of such assemblages, the actinic radiation curable,substantially all solids composition is comprised of a mixture of atleast one oligomer, at least one monomer, at least one photoinitiator,optionally at least one co-photoinitiator, at least one nano-filler,optionally at least one filler, and optionally at least onepolymerizable pigment dispersion. In a further embodiment, the means forirradiating so as to partially cure the coated surface and the means forirradiating so as to completely cure the coated surface are located atan irradiation station so as to not require the transport of the object.In still a further embodiment, the means for applying the composition islocated at an application station, wherein the object must be moved fromthe application station to the irradiation station. In yet a furtherembodiment, such assemblages further comprise a means for moving theobject from the application station to the irradiation station. In stillyet a further embodiment, the means for moving comprises a conveyerbelt.

In further or alternative embodiments, the irradiation station comprisesa means for limiting the exposure of actinic radiation to theapplication station. In yet further or alternative embodiment,assemblages further comprise a means for rotating the object around atleast one axis. In yet further or alternative embodiment, assemblagesfurther comprise a mounting station wherein the object to be coated isattached to a movable unit. In further embodiments, the movable unit iscapable of rotating the object around at least one axis. In further oralternative embodiments, the movable unit is capable of moving theobject from the application station to the irradiation station.

In still further or alternative embodiments, such assemblages furthercomprise a removal station wherein the completely cured coated object isremoved from the movable unit. In further embodiments, the completelycured coated object does not require cooling prior to removal from themovable unit.

In further or alternative embodiments, the means for applying includesspraying means, brushing means, rolling means, dipping means, bladecoating, and curtain coating means. In further embodiments, the meansfor applying includes a spraying means. In still further embodiments,the spraying means includes equipment for high volume low pressure(HVLP) spraying. In further or alternative embodiments, the means forapplying occurs at ambient temperature. In further or alternativeembodiments, the spraying means includes equipment for electrostaticspraying. In further or alternative embodiments, the spraying meansincludes equipment for air-assisted/airless spraying.

In further or alternative embodiments, the application station furthercomprises a means for reclaiming actinic radiation curable,substantially all solids composition that is non-adhering to the surfaceof the object. In still further embodiments, the reclaimed actinicradiation curable, substantially all solids composition is subsequentlyapplied to a different object.

In an embodiment of such assemblages for coating at least a portion of asurface, the actinic radiation curable, substantially all solidscomposition comprises at least one oligomer or a multiplicity ofoligomers present in the mixture between about 15-45% by weight. In afurther or alternative embodiments of the above aspect, the actinicradiation curable, substantially all solids composition comprises atleast one monomer or a multiplicity of monomers present in the mixturebetween about 25-65% by weight. In further or alternative embodiments,the actinic radiation curable, substantially all solids compositioncomprises at least one photoinitiator or a multiplicity ofphotoinitiators present in the mixture between about 2-10% by weight. Ina still further or alternate embodiment, the actinic radiation curable,substantially all solids composition comprises at least one nano-filleror a multiplicity of nano-fillers present in the mixture between about0.1-25% by weight. In further or alternative embodiments of theaforementioned aspect, the actinic radiation curable, substantially allsolids composition optionally comprises up to about 5% by weight of afiller or a multiplicity of fillers. In further or alternativeembodiments of the aforementioned aspect, the actinic radiation curable,substantially all solids composition optionally comprises up to about10% by weight of a polymerizable pigment dispersion or a multiplicity ofpolymerizable pigment dispersions. In still further or alternativeembodiments of the aforementioned aspect, the actinic radiation curable,substantially all solids composition mixture comprises 15-45% percent byweight of an oligomer or a multiplicity of oligomers, and 25-65% byweight of a monomer or a multiplicity of monomers. In further oralternative embodiments of this aspect, the actinic radiation curable,substantially all solids composition comprises 15-45% percent by weightof an oligomer or a multiplicity of oligomers, 25-65% by weight amonomer or a multiplicity of monomers and 2-10% by weight of aphotoinitiator or a multiplicity of photoinitiators. In still further oralternative embodiments, the actinic radiation curable, substantiallyall solids composition comprises 15-45% percent by weight of an oligomeror a multiplicity of oligomers, 25-65% by weight of a monomer or amultiplicity of monomers, 2-10% by weight of a photoinitiator or amultiplicity of photoinitiators, and 0.1-25% by weight of a nano-filleror a multiplicity of nano-fillers. In further or alternativeembodiments, the actinic radiation curable, substantially all solidscomprises 15-45% percent by weight an oligomer or a multiplicity ofoligomers, 25-65% by weight of a monomer or a multiplicity of monomers,2-10% by weight of a photoinitiator or a multiplicity ofphotoinitiators, 0.1-25% by weight of a nano-filler or a multiplicity ofnano-fillers, and up to about 5% by weight of a filler or a multiplicityof fillers. In even further or alternative embodiments, the actinicradiation curable, substantially all solids composition comprises 15-45%percent by weight an oligomer or a multiplicity of oligomers, 30-65% byweight of a monomer or a multiplicity of monomers, 2-10% by weight of aphotoinitiator or a multiplicity of photoinitiators, 0.1-5% by weight ofa nano-filler or a multiplicity of nano-fillers, up to about 5% byweight of a filler or a multiplicity of fillers, and up to about 10% byweight of a polymerizable pigment dispersion or a multiplicity ofpolymerizable pigment dispersions; whereby the room temperatureviscosity of the composition is up to about 500 centipoise.

In further or alternative embodiments, the first actinic radiation ofthe assemblage for coating at least a portion of a surface includesactinic radiation selected from the group consisting of visibleradiation, near visible radiation, ultra-violet (UV) radiation, andcombinations thereof. In further or alternative embodiments, the secondactinic radiation of the assemblage for coating at least a portion of asurface includes actinic radiation selected from the group consisting ofvisible radiation, near visible radiation, ultra-violet (UV) radiation,and combinations thereof. In further or alternative embodiments, theirradiation station includes an arrangement of mirrors.

In further or alternative embodiments of this aspect, the objects beingcoated are leaf springs.

In another aspect are processes for coating a at least a portion ofsurface of flexible objects (by way of example only, metal or plasticobjects), or objects comprising angular features, with an actinicradiation curable, substantially all solids composition comprisingattaching the object onto a conveying means; applying an actinicradiation curable composition at an application station onto the surfaceof the object; moving the coated object via the conveying means to anirradiation station; irradiating and partially curing the coated surfaceat the irradiation station with a first actinic radiation; andirradiating and completely curing the coated surface at the irradiationstation with a second actinic radiation; wherein the cured compositionis a flexible, corrosion resistant, abrasion resistant and scratchresistant coating with 99+% adhesion after 10 days at 110 F in 100%humidity, and/or a 180 degree bend around a mandrel, such as, by way ofexample only, a half inch mandrel.

In further embodiments, such processes further comprise attaching theobject to a rotatable spindle prior to the application step. In furtheror alternative embodiments, such processes further comprise moving theconveying means after attaching the object to the rotatable spindle soas to locate the object near an application station. In furtherembodiments, such processes further comprise applying an actinicradiation curable composition at the application station as the spindleholding the object rotates. In further embodiments, the conveying meanscomprises a conveyer belt.

In further or alternative embodiments, the irradiation station comprisesa curing chamber containing a first actinic radiation source and asecond actinic radiation source.

In further embodiments, such processes further comprise moving thecompletely cured coated object via the conveying means outside thecuring chamber wherein the coated object is packed for storage orshipment.

In one embodiment of such processes for coating at least a portion of asurface, the actinic radiation curable, substantially all solidscomposition may comprise comprises at least one oligomer or amultiplicity of oligomers present in the mixture between about 15-45% byweight. In a further or alternative embodiments of the above aspect, theactinic radiation curable, substantially all solids compositioncomprises at least one monomer or a multiplicity of monomers present inthe mixture between about 25-65% by weight. In further or alternativeembodiments, the actinic radiation curable, substantially all solidscomposition comprises at least one photoinitiator or a multiplicity ofphotoinitiators present in the mixture between about 2-10% by weight. Ina still further or alternate embodiment, the actinic radiation curable,substantially all solids composition comprises at least one nano-filleror a multiplicity of nano-fillers present in the mixture between about0.1-25% by weight. In further or alternative embodiments of theaforementioned aspect, the actinic radiation curable, substantially allsolids composition optionally comprises up to about 5% by weight of afiller or a multiplicity of fillers. In further or alternativeembodiments of the aforementioned aspect, the actinic radiation curable,substantially all solids composition optionally comprises up to about10% by weight of a polymerizable pigment dispersion or a multiplicity ofpolymerizable pigment dispersions. In still further or alternativeembodiments of the aforementioned aspect, the actinic radiation curable,substantially all solids composition mixture comprises 15-45% percent byweight of an oligomer or a multiplicity of oligomers, and 25-65% byweight of a monomer or a multiplicity of monomers. In further oralternative embodiments of this aspect, the actinic radiation curable,substantially all solids composition comprises 15-45% percent by weightof an oligomer or a multiplicity of oligomers, 25-65% by weight amonomer or a multiplicity of monomers and 2-10% by weight of aphotoinitiator or a multiplicity of photoinitiators. In still further oralternative embodiments, the actinic radiation curable, substantiallyall solids composition comprises 15-45% percent by weight of an oligomeror a multiplicity of oligomers, 25-65% by weight of a monomer or amultiplicity of monomers, 2-10% by weight of a photoinitiator or amultiplicity of photoinitiators, and 0.1-25% by weight of a nano-filleror a multiplicity of nano-fillers. In further or alternativeembodiments, the actinic radiation curable, substantially all solidscomprises 15-45% percent by weight an oligomer or a multiplicity ofoligomers, 25-65% by weight of a monomer or a multiplicity of monomers,2-10% by weight of a photoinitiator or a multiplicity ofphotoinitiators, 0.1-25% by weight of a nano-filler or a multiplicity ofnano-fillers, and up to about 5% by weight of a filler or a multiplicityof fillers. In even further or alternative embodiments, the actinicradiation curable, substantially all solids composition comprises 15-45%percent by weight an oligomer or a multiplicity of oligomers, 30-65% byweight of a monomer or a multiplicity of monomers, 2-10% by weight of aphotoinitiator or a multiplicity of photoinitiators, 0.1-5% by weight ofa nano-filler or a multiplicity of nano-fillers, up to about 5% byweight of a filler or a multiplicity of fillers, and up to about 10% byweight of a polymerizable pigment dispersion or a multiplicity ofpolymerizable pigment dispersions; whereby the room temperatureviscosity of the composition is up to about 500 centipoise.

In further or alternative embodiments, the application station comprisesequipment for electrostatic spray. In further or alternativeembodiments, the application station comprises equipment suitable forair-assisted/airless spraying. In further or alternative embodiments,the application station comprises equipment suitable for High Volume LowPressure (HVLP) coatings application. In either case, further oralternative embodiments include processes wherein the coating is appliedin a single application, or the coating is applied in multipleapplications. Further, in either case, further or alternativeembodiments include processes wherein the surface is partially coveredby the coating, or the surface is fully covered by the coating.

In further or alternative embodiments, the time between the firstactinic radiation step and the second actinic radiation step is lessthan 5 minutes. In further embodiments, the time between the firstactinic radiation step and the second actinic radiation step is lessthan 1 minute. In further embodiments, the time between the firstactinic radiation step and the second actinic radiation step is lessthan 15 seconds.

In further or alternative embodiments, the length of time of the firstactinic radiation step is shorter than the length of time of the secondactinic radiation step. In further or alternative embodiments, thelength of time of the first actinic radiation step is longer than thelength of time of the second actinic radiation step. In further oralternative embodiments, the length of time of the first actinicradiation step is identical to the length of time of the second actinicradiation step.

In further or alternative embodiments, the irradiation station includesat least one light capable of providing actinic radiation selected fromthe group consisting of visible radiation, near visible radiation,ultra-violet (UV) radiation, and combinations thereof.

In further or alternative embodiments, the irradiation station includesat least one light source capable of providing actinic radiationselected from the group consisting of UV-A radiation, UV-B radiation,UV-B radiation, UV-C radiation, UV-D radiation, or combinations thereof.

In further or alternative embodiments, the irradiation station includesan arrangement of mirrors such that the coated surface is cured in threedimensions. In further or alternative embodiments, the irradiationstation includes an arrangement of light sources such that the coatedsurface is cured in three dimensions. In further embodiments, each lightsource emits different spectral wavelength ranges. In furtherembodiments, the different light sources have partially overlappingspectral wavelength ranges.

In another aspect are production lines for coating at least a portion ofa surface of flexible objects (by way of example only, metal or plasticobjects), or objects comprising angular features, with an actinicradiation curable, substantially all solids composition comprising aprocess comprising attaching the object onto a conveying means; applyingan actinic radiation curable composition at an application station ontothe surface of the object; moving the coated object via the conveyingmeans to an irradiation station; irradiating and partially curing thecoated surface at the irradiation station with a first actinicradiation; and irradiating and completely curing the coated surface atthe irradiation station with a second actinic radiation; wherein thecured composition is a flexible, corrosion resistant, abrasion resistantand scratch resistant coating with 99+% adhesion after 10 days at 110 Fin 100% humidity, and/or a 180 degree bend around a mandrel, such as, byway of example only, a half inch mandrel.

In another aspect are facilities or factories for producing objectscoated at least in part with an actinic radiation cured substantiallyall solids composition comprising at least one production line forcoating a surface of an object with an actinic radiation curable,substantially all solids composition comprising a process comprisingattaching the object onto a conveying means; applying an actinicradiation curable composition at an application station onto the surfaceof the object; moving the coated object via the conveying means to anirradiation station; irradiating and partially curing the coated surfaceat the irradiation station with a first actinic radiation; andirradiating and completely curing the coated surface at the irradiationstation with a second actinic radiation; wherein the cured compositionis a flexible, corrosion resistant, abrasion resistant and scratchresistant coating with 99+% adhesion after 10 days at 110 F in 100%humidity, and/or a 180 degree bend around a mandrel, such as, by way ofexample only, a half inch mandrel.

In another aspect the actinic radiation curable, substantially allsolids compositions described herein are comprised of a mixture of atleast one oligomer, at least one monomer, at least one photoinitiator,at least one nano-filler, and at least one corrosion inhibitor, whereinthe cured composition is a slick, abrasion and scratch resistant coatingwith at least 6 H hardness.

In an embodiment of the aforementioned aspect, the actinic radiationcurable, substantially all solids composition comprises at least oneoligomer or a multiplicity of oligomers present in the mixture betweenabout 15-45% by weight. In further or alternative embodiments the atleast one oligomer comprises a slip and flow enhancing oligomer presentin the actinic radiation curable, substantially all solids compositionmixture between about 15-45% by weight. In still further or alternativeembodiments of the above aspect, the actinic radiation curable,substantially all solids composition comprises at least one monomer or amultiplicity of monomers present in the mixture between about 30-65% byweight. In further or alternative embodiments, the actinic radiationcurable, substantially all solids composition comprises at least onephotoinitiator or a multiplicity of photoinitiators present in themixture between about 2-10% by weight. In a still further or alternateembodiment, the actinic radiation curable, substantially all solidscomposition comprises at least one nano-filler or a multiplicity ofnano-fillers present in the mixture between about 0.1-5% by weight. Infurther or alternative embodiments of the aforementioned aspect, theactinic radiation curable, substantially all solids compositioncomprises at least one corrosion inhibitor or a multiplicity ofcorrosion inhibitors present in the mixture between about 0.01-2% byweight. In further or alternative embodiments of the aforementionedaspect, the actinic radiation curable, substantially all solidscomposition optionally comprises up to about 15% by weight of apolymerizable pigment dispersion or a multiplicity of polymerizablepigment dispersions. In still further or alternative embodiments of theaforementioned aspect, the actinic radiation curable, substantially allsolids composition mixture comprises 15-45% percent by weight of anoligomer or a multiplicity of oligomers, and 30-65% by weight of amonomer or a multiplicity of monomers. In further or alternativeembodiments of this aspect, the actinic radiation curable, substantiallyall solids composition comprises 15-45% percent by weight of an oligomeror a multiplicity of oligomers, 30-65% by weight a monomer or amultiplicity of monomers and 2-10% by weight of a photoinitiator or amultiplicity of photoinitiators. In still further or alternativeembodiments, the actinic radiation curable, substantially all solidscomposition comprises 5-45% percent by weight of an oligomer or amultiplicity of oligomers, 30-65% by weight of a monomer or amultiplicity of monomers, 2-10% by weight of a photoinitiator or amultiplicity of photoinitiators, and 0.1-5% by weight of a nano-filleror a multiplicity of nano-fillers. In further or alternativeembodiments, the actinic radiation curable, substantially all solidscomprises 15-45% percent by weight an oligomer or a multiplicity ofoligomers, 30-65% by weight of a monomer or a multiplicity of monomers,2-10% by weight of a photoinitiator or a multiplicity ofphotoinitiators, 0.1-5% by weight of a nano-filler or a multiplicity ofnano-fillers, and up to about 15% by weight of a polymerizable pigmentdispersion or a multiplicity of polymerizable pigment dispersions. Ineven further or alternative embodiments, the actinic radiation curable,substantially all solids composition comprises 15-45% percent by weightan oligomer or a multiplicity of oligomers, 30-65% by weight of amonomer or a multiplicity of monomers, 2-10% by weight of aphotoinitiator or a multiplicity of photoinitiators, 0.1-5% by weight ofa nano-filler or a multiplicity of nano-fillers, up to about 15% byweight of a polymerizable pigment dispersion or a multiplicity ofpolymerizable pigment dispersions, and 0.01-2% by weight of a corrosioninhibitor or a multiplicity of corrosion inhibitors; whereby the roomtemperature viscosity of the composition is up to about 500 centipoise.

In further or alternative embodiments of this aspect, the oligomers maybe selected from a group consisting of urethane acrylates, aliphaticurethane acrylates, aliphatic urethane triacrylate/monomer blends,aliphatic urethane triacrylates blended with 1,6-hexanediol acrylates,hexafunctional urethane acrylates, siliconized urethane acrylates,aliphatic siliconized urethane acrylates, CN990, and combinationsthereof. In another or alternative embodiments the monomers are selectedfrom a group consisting of trimethylolpropane triacrylates,2-phenoxyethyl acrylates, isobornyl acrylates, propoxylated glyceryltriacrylates, acrylate ester derivatives, methacrylate esterderivatives, tripropylene glycol diacrylate, and combinations thereof.

In still further or alternative embodiments, the photoinitiators may beselected from a group consisting ofdiphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, IRGACURE® 500, Lucirin®TPO, dimethyl ketal, benzophenone, 1-hydroxycyclohexyl phenyl ketone,2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2,4,6,-trimethylbenzophenone,4-methylbenzophenone,oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone), andcombinations thereof. In another or alternative embodiments, the actinicradiation curable, substantially all solids composition furthercomprises up to about 2% of a co-photoinitiator selected from amineacrylates, thioxanthone, benzyl methyl ketal, and combinations thereof.

In further or alternative embodiments of the aforementioned aspect, thenano-fillers may be selected from a group consisting of nano-aluminumoxide, nano-silicon dioxide, nano-zirconium oxide, nano-zirconiumdioxides, nano-silicon carbide, nano-silicon nitride, nano-sialon,nano-aluminum nitride, nano-bismuth oxide, nano-cerium oxide,nano-copper oxide, nano-iron oxide, nano-nickel titanate, nano-niobiumoxide, nano-rare earth oxide, nano-silver oxide, nano-tin oxide, andnano-titanium oxide, and combinations thereof. In addition, the averagesize of the nano-filler particles is less than 100 nanometers. In stillfurther or alternative embodiments, the corrosion inhibitor is M-235.

In further or alternative embodiments, the polymerizable pigmentdispersions are comprised of at least one pigment attached to anactivated resin; wherein the activated resin is selected from a groupconsisting of acrylate resins, methacrylate resins, and vinyl resins,and the pigment is selected from a group consisting of carbon black,rutile titanium dioxide, organic red pigment, phthalo blue pigment, redoxide pigment, isoindoline yellow pigment, phthalo green pigment,quinacridone violet, carbazole violet, masstone black, light lemonyellow oxide, light organic yellow, transparent yellow oxide, diarylideorange, quinacridone red, organic scarlet, light organic red, and deeporganic red.

In further or alternative embodiments, the actinic radiation curable,substantially all solids composition is suitable as a substitute for ahard chrome coating on an object. In still further or alternativeembodiment, the actinic radiation curable, substantially all solidscomposition is suitable as a substitute for TEFLON® coatings, coatingscomprising TEFLON®, or a TEFLON® like coatings used to coat objects.

In further or alternative embodiments, the coating may be applied to thesurface by means of spraying, brushing, rolling, dipping, blade coating,curtain coating or a combination thereof. Further, the means of sprayingincludes, but is not limited to, the use of a high pressure low volumespraying systems, air-assisted/airless spraying systems, orelectrostatic spraying systems. In further or alternative embodiments,the coating is applied in a single application, or in multipleapplications. In further or alternative embodiments, the surfaces ofobjects are partially covered by the coating, or in a still further oralternative embodiments, the surfaces of objects are fully covered bythe coating.

In further or alternative embodiments, object surface becomes partiallycovered, or becomes fully covered by the uncured coating. In further oralternative embodiments, the object with an uncured coated surfacecomprises metal, fiber glass, paper, ceramic, glass, wood, and plastic.

In further or alternative embodiments, the coated surfaces are partiallycured by exposure of uncured coated surfaces to a first source ofactinic radiation. In further or alternative embodiments, the coatedsurfaces are fully cured by exposure of the partially cured coatedsurface to a second source of actinic radiation. In further oralternative embodiments, the fully cured surfaces are hard, slick,abrasion resistant, or any combinations thereof.

In further or alternative embodiments, the actinic radiation is selectedfrom the group consisting of visible radiation, near visible radiation,ultra-violet (UV) radiation, and combinations thereof. Further, the UVradiation is selected from the group consisting of UV-A radiation, UV-Bradiation, UV-B radiation, UV-C radiation, UV-D radiation, orcombinations thereof.

In further or alternative embodiments, the completely cured coatedsurface is part of articles of manufacture. In further or alternativeembodiments, the articles of manufacture include the completely curedcoated surface. In further or alternative embodiments, the article ofmanufacture coated may be an article of manufacture wherein at least oneof its functions would be enhanced or improved by the presence of a“hard chrome” coating. In further or alternative embodiments, thearticle of manufacture of is selected from the group comprisinghydraulic rods, hydraulic cylinders, jet engine components, dieselcylinder liners, pneumatic struts, shock absorbers, aircraft landinggear, ball joints, axels, railroad wheel bearings and couplers, tool anddie parts, and molds for the plastic and rubber industry.

In a further aspect the method for producing the actinic radiationcurable, substantially all solids composition involves adding thecomponents, for instance, by way of example only, least one oligomer, atleast one monomer, at least one photoinitiator, optionally at least oneco-photoinitiator, at least one nano-filler, at least one corrosioninhibitor, and optionally at least one polymerizable pigment dispersion,and using a means for mixing the components together to form a smoothcomposition. In further or alternative embodiments, the composition maybe mixed in or transferred to a suitable container, such as, but notlimited to, a can.

In another aspect are assemblages for coating at least a portion of asurface of an object with an actinic radiation curable, substantiallyall solids composition comprising a means for applying to the object anactinic radiation curable, substantially all solids composition; a meansfor irradiating the applied coating with a first actinic radiation so asto partially cure the applied coating on the surface; and a means forirradiating the object with a second actinic radiation so as tocompletely cure the partially cured coating on the surface, wherein thecured composition is a slick, abrasion and scratch resistant coatingwith at least 6 H hardness.

In one embodiment of such assemblages, the actinic radiation curable,substantially all solids composition is comprised of a mixture of atleast one oligomer, at least one monomer, at least one photoinitatiors,optionally at least one co-photoinitiators, at least one nano-fillers,at least one corrosion inhibitors, and optionally at least onepolymerizable pigment dispersions. In a further embodiment, the meansfor irradiating so as to partially cure the coated surface and the meansfor irradiating so as to completely cure the coated surface are locatedat an irradiation station so as to not require the transport of theobject. In still a further embodiment, the means for applying thecomposition is located at an application station, wherein the objectmust be moved from the application station to the irradiation station.In yet a further embodiment, such assemblages further comprise a meansfor moving the object from the application station to the irradiationstation. In still yet a further embodiment, the means for movingcomprises a conveyer belt.

In further or alternative embodiments, the irradiation station comprisesa means for limiting the exposure of actinic radiation to theapplication station. In yet further or alternative embodiment,assemblages further comprise a means for rotating the object around atleast one axis. In yet further or alternative embodiment, assemblagesfurther comprise a mounting station wherein the object to be coated isattached to a movable unit. In further embodiments, the movable unit iscapable of rotating the object around at least one axis. In further oralternative embodiments, the movable unit is capable of moving theobject from the application station to the irradiation station.

In still further or alternative embodiments, such assemblages furthercomprise a removal station wherein the completely cured coated object isremoved from the movable unit. In further embodiments, the completelycured coated object does not require cooling prior to removal from themovable unit.

In further or alternative embodiments, the means for applying includesspraying means, brushing means, rolling means, dipping means, bladecoating, and curtain coating means. In further embodiments, the meansfor applying includes a spraying means. In still further embodiments,the spraying means includes equipment for high volume low pressure(HVLP) spraying. In further or alternative embodiments, the means forapplying occurs at ambient temperature. In further or alternativeembodiments, the spraying means includes equipment for electrostaticspraying. In further or alternative embodiments, the spraying meansincludes equipment for air-assisted/airless spraying.

In further or alternative embodiments, the application station furthercomprises a means for reclaiming actinic radiation curable,substantially all solids composition that is non-adhering to the surfaceof the object. In still further embodiments, the reclaimed actinicradiation curable, substantially all solids composition is subsequentlyapplied to a different object.

In one embodiment of such assemblages for coating at least a portion ofa surface, the actinic radiation curable, substantially all solidscomposition comprises at least one oligomer or a multiplicity ofoligomers present in the mixture between about 15-45% by weight. Infurther or alternative embodiments the at least one oligomer comprises aslip and flow enhancing oligomer present in the actinic radiationcurable, substantially all solids composition mixture between about15-45% by weight. In still further or alternative embodiments of theabove aspect, the actinic radiation curable, substantially all solidscomposition comprises at least one monomer or a multiplicity of monomerspresent in the mixture between about 30-65% by weight. In further oralternative embodiments, the actinic radiation curable, substantiallyall solids composition comprises at least one photoinitiator or amultiplicity of photoinitiators present in the mixture between about2-10% by weight. In a still further or alternate embodiment, the actinicradiation curable, substantially all solids composition comprises atleast one nano-filler or a multiplicity of nano-fillers present in themixture between about 0.1-5% by weight. In further or alternativeembodiments of the aforementioned aspect, the actinic radiation curable,substantially all solids composition comprises at least one corrosioninhibitor or a multiplicity of corrosion inhibitors present in themixture between about 0.01-2% by weight. In further or alternativeembodiments of the aforementioned aspect, the actinic radiation curable,substantially all solids composition optionally comprises up to about15% by weight of a polymerizable pigment dispersion or a multiplicity ofpolymerizable pigment dispersions. In still further or alternativeembodiments of the aforementioned aspect, the actinic radiation curable,substantially all solids composition mixture comprises 15-45% percent byweight of an oligomer or a multiplicity of oligomers, and 30-65% byweight of a monomer or a multiplicity of monomers. In further oralternative embodiments of this aspect, the actinic radiation curable,substantially all solids composition comprises 15-45% percent by weightof an oligomer or a multiplicity of oligomers, 30-65% by weight amonomer or a multiplicity of monomers and 2-10% by weight of aphotoinitiator or a multiplicity of photoinitiators. In still further oralternative embodiments, the actinic radiation curable, substantiallyall solids composition comprises 5-45% percent by weight of an oligomeror a multiplicity of oligomers, 30-65% by weight of a monomer or amultiplicity of monomers, 2-10% by weight of a photoinitiator or amultiplicity of photoinitiators, and 0.1-5% by weight of a nano-filleror a multiplicity of nano-fillers. In further or alternativeembodiments, the actinic radiation curable, substantially all solidscomprises 15-45% percent by weight an oligomer or a multiplicity ofoligomers, 30-65% by weight of a monomer or a multiplicity of monomers,2-10% by weight of a photoinitiator or a multiplicity ofphotoinitiators, 0.1-5% by weight of a nano-filler or a multiplicity ofnano-fillers, and up to about 15% by weight of a polymerizable pigmentdispersion or a multiplicity of polymerizable pigment dispersions. Ineven further or alternative embodiments, the actinic radiation curable,substantially all solids composition comprises 15-45% percent by weightan oligomer or a multiplicity of oligomers, 30-65% by weight of amonomer or a multiplicity of monomers, 2-10% by weight of aphotoinitiator or a multiplicity of photoinitiators, 0.1-5% by weight ofa nano-filler or a multiplicity of nano-fillers, up to about 15% byweight of a polymerizable pigment dispersion or a multiplicity ofpolymerizable pigment dispersions, and 0.01-2% by weight of a corrosioninhibitor or a multiplicity of corrosion inhibitors; whereby the roomtemperature viscosity of the composition is up to about 500 centipoise.

In further or alternative embodiments, the first actinic radiation ofthe assemblage for coating at least a portion of a surface includesactinic radiation selected from the group consisting of visibleradiation, near visible radiation, ultra-violet (UV) radiation, andcombinations thereof. In further or alternative embodiments, the secondactinic radiation of the assemblage for coating at least a portion of asurface includes actinic radiation selected from the group consisting ofvisible radiation, near visible radiation, ultra-violet (UV) radiation,and combinations thereof. In further or alternative embodiments, theirradiation station includes an arrangement of mirrors.

In further or alternative embodiments of this aspect, the objects beingcoated are hydraulic rods.

In another aspect are processes for coating a at least a portion ofsurface of an object with an actinic radiation curable, substantiallyall solids composition comprising attaching the object onto a conveyingmeans; applying an actinic radiation curable composition at anapplication station onto the surface of the object; moving the coatedobject via the conveying means to an irradiation station; irradiatingand partially curing the coated surface at the irradiation station witha first actinic radiation; and irradiating and completely curing thecoated surface at the irradiation station with a second actinicradiation; wherein the cured composition is a slick, abrasion andscratch resistant coating with at least 6 H hardness.

In further embodiments, such processes further comprise attaching theobject to a rotatable spindle prior to the application step. In furtheror alternative embodiments, such processes further comprise moving theconveying means after attaching the object to the rotatable spindle soas to locate the object near an application station. In furtherembodiments, such processes further comprise applying an actinicradiation curable composition at the application station as the spindleholding the object rotates. In further embodiments, the conveying meanscomprises a conveyer belt.

In further or alternative embodiments, the irradiation station comprisesa curing chamber containing a first actinic radiation source and asecond actinic radiation source.

In further embodiments, such processes further comprise moving thecompletely cured coated object via the conveying means outside thecuring chamber wherein the coated object is packed for storage orshipment.

In one embodiment of such processes for coating at least a portion of asurface, the actinic radiation curable, substantially all solidscomposition may comprise comprises at least one oligomer or amultiplicity of oligomers present in the mixture between about 15-45% byweight. In further or alternative embodiments the at least one oligomercomprises a slip and flow enhancing oligomer present in the actinicradiation curable, substantially all solids composition mixture betweenabout 15-45% by weight. In still further or alternative embodiments ofthe above aspect, the actinic radiation curable, substantially allsolids composition comprises at least one monomer or a multiplicity ofmonomers present in the mixture between about 30-65% by weight. Infurther or alternative embodiments, the actinic radiation curable,substantially all solids composition comprises at least onephotoinitiator or a multiplicity of photoinitiators present in themixture between about 2-10% by weight. In a still further or alternateembodiment, the actinic radiation curable, substantially all solidscomposition comprises at least one nano-filler or a multiplicity ofnano-fillers present in the mixture between about 0.1-5% by weight. Infurther or alternative embodiments of the aforementioned aspect, theactinic radiation curable, substantially all solids compositioncomprises at least one corrosion inhibitor or a multiplicity ofcorrosion inhibitors present in the mixture between about 0.01-2% byweight. In further or alternative embodiments of the aforementionedaspect, the actinic radiation curable, substantially all solidscomposition optionally comprises up to about 15% by weight of apolymerizable pigment dispersion or a multiplicity of polymerizablepigment dispersions. In still further or alternative embodiments of theaforementioned aspect, the actinic radiation curable, substantially allsolids composition mixture comprises 15-45% percent by weight of anoligomer or a multiplicity of oligomers, and 30-65% by weight of amonomer or a multiplicity of monomers. In further or alternativeembodiments of this aspect, the actinic radiation curable, substantiallyall solids composition comprises 15-45% percent by weight of an oligomeror a multiplicity of oligomers, 30-65% by weight a monomer or amultiplicity of monomers and 2-10% by weight of a photoinitiator or amultiplicity of photoinitiators. In still further or alternativeembodiments, the actinic radiation curable, substantially all solidscomposition comprises 5-45% percent by weight of an oligomer or amultiplicity of oligomers, 30-65% by weight of a monomer or amultiplicity of monomers, 2-10% by weight of a photoinitiator or amultiplicity of photoinitiators, and 0.1-5% by weight of a nano-filleror a multiplicity of nano-fillers. In further or alternativeembodiments, the actinic radiation curable, substantially all solidscomprises 15-45% percent by weight an oligomer or a multiplicity ofoligomers, 30-65% by weight of a monomer or a multiplicity of monomers,2-10% by weight of a photoinitiator or a multiplicity ofphotoinitiators, 0.1-5% by weight of a nano-filler or a multiplicity ofnano-fillers, and up to about 15% by weight of a polymerizable pigmentdispersion or a multiplicity of polymerizable pigment dispersions. Ineven further or alternative embodiments, the actinic radiation curable,substantially all solids composition comprises 15-45% percent by weightan oligomer or a multiplicity of oligomers, 30-65% by weight of amonomer or a multiplicity of monomers, 2-10% by weight of aphotoinitiator or a multiplicity of photoinitiators, 0.1-5% by weight ofa nano-filler or a multiplicity of nano-fillers, up to about 15% byweight of a polymerizable pigment dispersion or a multiplicity ofpolymerizable pigment dispersions, and 0.01-2% by weight of a corrosioninhibitor or a multiplicity of corrosion inhibitors; whereby the roomtemperature viscosity of the composition is up to about 500 centipoise.

In further or alternative embodiments, the application station comprisesequipment for electrostatic spray. In further or alternativeembodiments, the application station comprises equipment suitable forair-assisted/airless spraying. In further or alternative embodiments,the application station comprises equipment suitable for High pressureLow Volume (HVLP) coatings application. In either case, further oralternative embodiments include processes wherein the coating is appliedin a single application, or the coating is applied in multipleapplications. Further, in either case, further or alternativeembodiments include processes wherein the surface is partially coveredby the coating, or the surface is fully covered by the coating.

In further or alternative embodiments, the time between the firstactinic radiation step and the second actinic radiation step is lessthan 5 minutes. In further embodiments, the time between the firstactinic radiation step and the second actinic radiation step is lessthan 1 minute. In further embodiments, the time between the firstactinic radiation step and the second actinic radiation step is lessthan 15 seconds.

In further or alternative embodiments, the length of time of the firstactinic radiation step is shorter than the length of time of the secondactinic radiation step. In further or alternative embodiments, thelength of time of the first actinic radiation step is longer than thelength of time of the second actinic radiation step. In further oralternative embodiments, the length of time of the first actinicradiation step is identical to the length of time of the second actinicradiation step.

In further or alternative embodiments, the irradiation station includesat least one light capable of providing actinic radiation selected fromthe group consisting of visible radiation, near visible radiation,ultra-violet (UV) radiation, and combinations thereof.

In further or alternative embodiments, the irradiation station includesat least one light source capable of providing actinic radiationselected from the group consisting of UV-A radiation, UV-B radiation,UV-B radiation, UV-C radiation, UV-D radiation, or combinations thereof.

In further or alternative embodiments, the irradiation station includesan arrangement of mirrors such that the coated surface is cured in threedimensions. In further or alternative embodiments, the irradiationstation includes an arrangement of light sources such that the coatedsurface is cured in three dimensions. In further embodiments, each lightsource emits different spectral wavelength ranges. In furtherembodiments, the different light sources have partially overlappingspectral wavelength ranges.

In another aspect are production lines for coating at least a portion ofa surface of an object with an actinic radiation curable, substantiallyall solids composition comprising a process comprising attaching theobject onto a conveying means; applying an actinic radiation curablecomposition at an application station onto the surface of the object;moving the coated object via the conveying means to an irradiationstation; irradiating and partially curing the coated surface at theirradiation station with a first actinic radiation; and irradiating andcompletely curing the coated surface at the irradiation station with asecond actinic radiation; wherein the cured composition is a slick,abrasion and scratch resistant coating with at least 6 H hardness.

In another aspect are facilities or factories for producing objectscoated at least in part with an actinic radiation cured substantiallyall solids composition comprising at least one production line forcoating a surface of an object with an actinic radiation curable,substantially all solids composition comprising a process comprisingattaching the object onto a conveying means; applying an actinicradiation curable composition at an application station onto the surfaceof the object; moving the coated object via the conveying means to anirradiation station; irradiating and partially curing the coated surfaceat the irradiation station with a first actinic radiation; andirradiating and completely curing the coated surface at the irradiationstation with a second actinic radiation; wherein the cured compositionis a slick, abrasion and scratch resistant coating with at least 6 Hhardness.

INCORPORATION BY REFERENCE

All publications, patents and patent applications mentioned in thisspecification are herein incorporated by reference in their entirety tothe same extent as if each individual publication, patent or patentapplication was specifically and individually indicated to beincorporated by reference.

BRIEF DESCRIPTION OF THE FIGURES

A better understanding of the features and advantages of the presentmethods and compositions may be obtained by reference to the followingdetailed description that sets forth illustrative embodiments, in whichthe principles of our methods, compositions, devices and apparatuses areutilized, and the accompanying drawings of which:

FIG. 1 is a flowchart of one possible process for coating a flexibleobject and/or an angular object with the coating compositions describedherein.

FIG. 2 is flowchart of one possible assemblage for coating flexibleand/or angular objects with the coating compositions described herein.

FIG. 3 is an illustration of possible components required to obtain thecoating compositions described herein.

FIG. 4 is an illustration of one method by which the coatings describedherein are applied.

FIG. 5 is an illustration of one method for curing the coating.

FIG. 6 is a flowchart of the process used to obtain objects with acoating having hardness properties, a coating having slip properties, ora coating with slip and hardness properties.

DETAILED DESCRIPTION OF THE INVENTION

The 100% solids, actinic radiation curable coating compositions, methodsof applying the compositions, coated surfaces and coated articlesdescribed herein, materially enhance the quality of the environment byincorporation of components which are zero or near zero volatile organiccompounds (VOC's). Further, such components are essentially non-volatileand therefore have zero or near zero emissions. Such a decrease inemissions significantly decreases air pollution, especially incomparison to the air pollution encountered with coating compositionusing volatile solvents. In addition, any water and soil pollutionassociated with waste disposal from processes using coating compositionusing volatile solvents is minimized using the methods described herein,thereby further contributing to and materially enhancing the quality ofthe environment. Furthermore, the 100% solids, actinic radiation curablecoating compositions, methods, processes and assemblages for applyingthe compositions, coated surfaces and coated articles described herein,utilize significantly less energy than processes using coatingcomposition using volatile solvents or water as a solvent, therebyconserving energy.

Glossary of Certain Terms

The term “abrasion resistance” as used herein, refers to the ability ofa material to resist damage that can lead to visible, deep or widetrenches. Thus, scratches are generally regarded as being more severethan what is referred to in the art as mar.

The term “actinic radiation” as used herein, refers to any radiationsource which can produce polymerization reactions, such as, by way ofexample only, ultraviolet radiation, near ultraviolet radiation, andvisible light.

The term “angular feature” as used herein, refers to features which havevarying angles and dimensions, such as, by way of example only, cornersof varying angles and dimensions. Angular features also include threedimensional features, such as, by way of example only, bumps, channels,grooves, lips, edges, and protrusions.

The term “co-photoinitiator,” as used herein, refers to a photoinitiatorwhich may be combined with another photoinitiator or photoinitiators.

The term “corrosion inhibitor”, as used herein, refers to an agent oragents which inhibit, or partially inhibit corrosion.

The term “corrosion resistance” as used herein, refers to the ability ofa material to resist oxidation damage.

The term “cure,” as used herein, refers to polymerization, at least inpart, of a coating composition.

The term “curable,” as used herein, refers to a coating compositionwhich is able to polymerize at least in part.

The term “curing booster”, as used herein, refers to an agent or agentswhich boost or otherwise enhance, or partially enhance, the curingprocess.

The term “filler” refers to a relatively inert substance, added tomodify the physical, mechanical, thermal, or electrical properties of acoating.

The term “flexible”, as used herein, refers to the ability to bend,twist, or compress without breaking, and the object can optionallyreturn back to a portion of its original shape or position.

The term “inorganic pigment”, as used herein, refers to ingredientswhich are particulate and substantially nonvolatile in use, and includesthose ingredients typically labeled as inerts, extenders, fillers or thelike in the paint and plastic trade.

The term “irradiating,” as used herein, refers to exposing a surface toactinic radiation.The term “milling” as used herein, refers to theprocesses of premixing, melting and grinding a powder coatingformulation to obtain a powder suitable for spraying.

The term “monomers,” as used herein, refers to substances containingsingle molecules that can link to oligomers and to each other.

The term “motor vehicle”, as used herein, refers to any vehicle which isself-propelled by mechanical or electrical power. Motor vehicles, by wayof example only, include automobiles, buses, trucks, tractors,recreational vehicles, and off-road vehicles.

The term “oligomers,” as used herein, refers to molecules containingseveral repeats of a single molecule.

The term “photoinitiators,” as used herein, refers to compounds thatabsorb ultra-violet light and use the energy of that light to promotethe formation of a dry layer of coating.

The term “polymerizable pigment dispersions,” as used herein, refers topigments attached to polymerizable resins which are dispersed in acoating composition.

The term “polymerizable resin” or “activated resin,” as used herein,refers to resins which possess reactive functional groups.

The term “pigment,” as used herein, refers to compounds which areinsoluble or partially soluble, and are used to impart color.

The term “scratch” as used herein, refers to physical deformationsresulting from mechanical or chemical abrasion.

The term “scratch resistance” as used herein, refers to the ability of amaterial to resist damage that can lead to visible, deep or widetrenches. Thus, scratches are generally regarded as being more severethan what is referred to in the art as mar.

The term “slip and flow enhancer”, as used herein, refers to componentor components, which enhance or partially enhance the flow and slipcharacteristics of a coating.

The terms “slip” and “slick” as used herein, refer to surfaces whichhave a low coefficient of friction two which allows contacting surfacesto easily move by each other.

The term “vehicle” as used herein, refers to the liquid portion ofsolvent based formulations, and can incorporate both the solvent and theresin.

Coatings

In general, solvent-based coating formulations incorporate four basictypes of materials: pigment(s), resin(s) (binder(s)), solvent(s), andadditives. Homogeneous pigment dispersions can be created by efficientmixing of insoluble raw pigment particle in the vehicle, and therebycreate opaque coatings. The resin makes up the non-volatile portion ofthe vehicle, and aids in adhesion, determines coating cohesiveness,affects gloss, and provides resistance to chemicals, water, andacids/bases. Three types of resins are generally used: multiuse resins(acrylics, vinyls, urethanes, polyesters); thermoset resins (alkyds,epoxides); and oils. The type of solvent used in such formulationsdepends on the resin and is either an organic solvent (such as alcohols,esters, ketones, glycol ethers, methylene chloride, trichloroethane, andpetroleum distillates), or water. Organic solvents are used tothin/dilute the coating compositions and act to evenly disperse thepaint composition over the surface and then evaporate quickly. However,due to their high volatility such organic solvents create high emissionconcentrations and are therefore classified as Volatile OrganicCompounds (VOC's) and Hazardous Air Pollutants (HAP's). These solventemissions are of concern to employers and employees in facilities inwhich such VOC's and HAP's are used, as overexposure can cause renaldamage or other health related difficulties. In addition, environmentalimpact, and potential fire hazards are other issues to consider whenusing coatings which incorporate organic solvents. Furthermore, coatingswhich incorporate organic solvents require large curing ovens toinitiate curing of the coating and to remove the solvent. All of theseissues require a significant financial commitment from the coating enduser, in terms of leasing or purchasing space for the large ovens, thecost of energy associated with the thermal curing process, possiblemedical expenses, potential environmental cleanup, and insurancepremiums.

Thermoset Powder Coatings and UV-curable Powder Coating

Powder-based coating compositions and aqueous-based formulations weredeveloped to address the issue of volatile emissions associated withnon-aqueous solvent-based coating compositions. Powder-based coatings,which can include thermoset or UV-cure formulations, may decreaseemissions, however due to the need for thermal melting, smoothing andcuring (for thermoset powders), such powder-based coatings also requireconsiderable time, space for large ovens, and energy. In addition,powder coatings also often display an “orange peel” appearance that maybe undesirable. Solid resins which possess UV-reactive moieties, andretain the melt and flow characteristics needed to produce high qualitycoatings, allow for the creation of UV-curable powder coatings. Thesepowder coatings combine the low energy, space efficient and fast curecharacteristics observed with UV curing, with the convenience of powdercoating application, such as electrostatic spraying. The use of UVcuring effectively separates the melt and flow stages from the curingstage, however, there still remains the requirement of large ovens forthe melt and flow stages, and the associated cost and space requirementsneeded to operate such ovens.

100% Solids, UV-curable Coating

Described herein are sprayable, 100% solids compositions, methods ofusing the compositions for coating surfaces, and the processes ofcoating surfaces. The 100% solids coating compositions described hereincomprise actinic radiation curable materials (by way of example,monomers and oligomers), photoinitiators, solid pigment dispersions,adhesion promoters, nano-fillers, and fillers for the coating ofsurfaces of flexible objects (by way of example only, metal or plasticobjects), or objects comprising angular features, and which may besprayed by conventional methods, including, but not limited to, HVLP,air-assisted/airless, or electrostatic bell in one coat, with noadditional heat applied. In addition, the 100% solids coatingcompositions described herein impart flexibility, corrosion resistance,abrasion resistance, improved gloss, improved adhesion, and can beeither opaque or have a clear coat finish.

The 100% solids UV-curable coating compositions described herein do notuse added solvent. This is achieved, in part, by the use of lowmolecular weight monomers which take the place of organic solvents.However, these monomers are not as volatile as organic solvents, andtherefore do not evaporate as readily as volatile organic solvents.Also, in contrast to volatile organic solvent, such monomers become anintegral component of the final coating and contribute to the finalcoating properties and characteristics. The 100% solids coatingcompositions described herein are easily applied to surfaces and curequickly by exposure to UV, without the use of large curing and dryingovens; thereby, decreasing production costs associated withowning/leasing space required for drying/curing ovens, along with theenergy cost associated with the operation of drying/curing ovens. Inaddition, a more efficient production process occurs because UV-curablecoating compositions can be applied in a single coating (i.e. one-coat),which decreases the coating time and allows for immediate “pack andship” capabilities. Also, the lack of volatile organic solvents in suchUV-curable coating compositions limits health, safety, and environmentalrisks posed by such solvents.

The 100% solids,UV-curable coating compositions described herein can beused to coat flexible objects, such as, by way of example only, metal orplastic objects, or to coat surfaces of flexible objects, such as, byway of example only, metal or plastic objects, or to coat flexibleobjects comprised of metallic or plastic components. In addition, the100% solids, UV-curable coating compositions described herein can beused to coat objects comprising angular features, such as, by way ofexample only, metal or plastic objects, or to coat flexible objectscomprising angular features, such as, by way of example only, metal orplastic objects.

The type of metal which may be coated using the 100% solids, UV-curablecoating compositions described herein includes, but is not limited to,ferrous metals and alloys (such as steel and pig iron), brass, bronze,aluminum, cobalt, copper, magnesium, nickel, titanium, tin or zinc, oralloys comprising aluminum, iron, cobalt, copper, magnesium, nickel,titanium, tin and/or zinc, plus galvanized steel, and electrogalvanizedsteel. In addition, the compositions described herein can be used tocoat any known form of metal, such as, but not limited to, cold-rolledmetal, extrusions, coil, welded parts, or cast parts. Metal surfaces, inparticular ferrous metals and alloys such as steels, are easily oxidizedto form surface oxides, herein referred to as rust, surface oxides ormetal oxides. However, other metal such as brass, bronze, aluminum,cobalt, copper, magnesium, nickel, titanium, tin or zinc, or alloyscomprising aluminum, iron, cobalt, copper, magnesium, nickel, titanium,tin and/or zinc also oxidize and form their corresponding surfaceoxides. Rust formation becomes even more likely and occurs more quicklyin environments having high humidity or salt content. Thus someprotective coating is needed to minimize the formation of surface oxideson metal surfaces. The resulting coatings obtained from the compositionsdescribed herein exhibits improved adhesion on metal surfaces andprovide increased corrosion resistance and abrasion resistance for thecoated metal.

When water based compositions are used to coat metal surfaces, the metalsurfaces can oxidize as the water evaporates during the coating, curingand drying stages by a process known as “flash-rusting”. Although it ispossible to reduce or eliminate the formation of flash rust withwater-borne coating compositions by drying with hot air blowers or theuse of vacuum systems, there is no added benefit with respect todecreasing energy costs, and there remains the need for large dryingovens. In contrast, the 100% solids, UV-curable coating compositionsdescribed herein do not utilize a solvent, including water, andtherefore avoids the potential for flash-rust formation. In addition,the use of such UV-curable compositions decreases the curing processtime, which may avoid flash-rust formation in higher humidityenvironments. Thus, the coating compositions described herein may beused to coat metal surfaces, such as iron, brass, bronze, aluminum,cobalt, copper, magnesium, nickel, titanium, tin or zinc, or alloyscomprising aluminum, iron, cobalt, copper, magnesium, nickel, titanium,tin and/or zinc, plus galvanized steel, and electrogalvanized steel,without incurring any flash rust.

The 100% solids, UV-curable coating compositions described herein useeither raw pigments or solid polymerizable pigment dispersions to impartopacity to the composition and the resulting coating. Solidpolymerizable pigment dispersions limit the need for “milling,” asrequired with raw pigments. Milling refers to the manufacture processesof premixing, melting and grinding raw pigments or powder compositionsinto a fine powder suitable for spraying onto a surface, or mixing intoa composition. The addition of these steps to the process results inincreased time and energy expenditures per article of manufacturecoated. Although raw pigments can be incorporated into the compositionsdescribed herein, the replacement of raw pigments with polymerizablepigment dispersions streamlines the coating process and removes theassociated milling costs, thus improving overall productivity andlowering business expenditures.

Pigment color properties such as strength, transparency/opacity, gloss,shade, rheology, and light and chemical stability, are generallyaffected to a greater or lesser extent by the size and distribution ofthe pigment particles in the vehicle in which they are embedded. Pigmentparticles normally exist in the form of primary particles (50 μm to 500μm), aggregates, agglomerates and flocculates. Primary particles areindividual crystals, whereas aggregate are collections of primaryparticles bound together at their crystal faces, and agglomerates are alooser type of arrangement with primary particles and aggregates joinedat corners and edges. Flocculates consist of primary particle aggregatesand agglomerates generally arranged in a fairly open structure, whichcan be broken down in shear. However, after the shear is removed, or adispersion is allowed to stand undisturbed, the flocculates can reform.The relationship between pigment particle size and the ability of apigment vehicle system to absorb visible electromagnetic radiation isreferred to as the color or tinctorial strength. The ability of a givenpigment to absorb light (tinctorial strength) increases with decreasingparticle diameter, and accordingly increased surface area. Thus, theability to maintain the pigment at a minimum pigment particle size willyield a maximum tinctorial strength. The primary purpose of a dispersionis to break down pigment aggregates and agglomerates into the primaryparticles, and therefore achieve optimal benefits of a pigment bothvisually and economically. When used in a coating composition pigmentdispersions exhibit increased tinctorial strength and provide enhancedgloss. However, of concern in obtaining an optimal dispersion is thenumber of processes involved in creating the pigment dispersion, such asagitating, shearing, milling, and grinding. If these processes are notaccurately controlled then the possibility exists for batch-to-batchcolor variation and poor color reproducibility. Alternatively,polymerizable pigment dispersions, which exhibit minimal aggregation andagglomeration, are simply mixed into the coating composition and therebyimprove color reproducibility by removing the need for these processesin the manufacturing and/or coating process. Furthermore, due to thereactive functionality of the polymerizable pigment dispersion, duringpolymerization the pigment becomes an integral part of the resultingcoating because it is attached to the reactive functionality. This mayimpart greater color stability relative to pigment dispersions whichsimply entrap the pigment particles in the coating matrix. Thus,coatings which incorporate polymerizable pigment dispersions exhibitimproved color reproducibility, and improved color stability, greatertinctorial strength and enhanced opacity and gloss. By way of exampleonly, compositions described herein are heavily pigmented and canexhibit acceptable opacity at thicknesses less than 50 microns.

The incorporation of various higher vapor pressure monomers/resins asthe vehicle in the 100% solids, UV curable compositions describedherein, effectively eliminates the need for organic solvents and theassociated solvent emission/evaporation issues. Consequently, thisobviates the need to incorporate air pollution/emission controltechnology into the manufacturing process. As a result, the methods andcompositions described herein can minimize the time, space and money formaintenance of air pollution control systems in an operation in which acoating step is integrated.

An additional advantage resulting from using the methods andcompositions described herein is that such compositions and methodsresult in the overall decrease in time required to apply, cure, and drythe coating. Although, conventional coating processes can be adapted tothe coating compositions and methods described herein, the use of UVradiation, rather than heat, to initiate the polymerization processsignificantly decreases the curing time per article coated. However, themethods and compositions described herein may include low amounts ofheat; for example, lamps used to provide the UV light for curing mayalso generate some heat. In addition, heat may be generated from othersources (including the ambient temperature of a facility); however, themethods and compositions described herein require minimal, if any,additional heat in order to achieve appropriate curing. In addition, thelack of solvent in the present compositions and methods removes therequirement for using heat to drive off solvent, a process which addssignificant time and cost to the coating procedure. Thus, the use of UVlight for curing, and the removal of solvent from the composition,dramatically decreases the time for completion of the total coatingprocess for each article coated, which allows for processing of moreparts in the same time needed for solvent-based methods, and fulfillingbatch orders requires less time.

The ability to minimize the usage of space for production, whether it isfloor space, wall space, or even ceiling space (in the situation whenobjects are hung from the ceiling), can be critical in terms ofproductivity, production costs and initial capital expenditure. Theremoval of the solvent from the UV-curable compositions described hereinallows for the removal of large ovens from the production line. Theseovens are used to cure and force the rapid evaporation of the solventwhen using solvent-based coating compositions. Removing the ovenssignificantly decreases the volume (floor, wall, and ceiling space)required for the production system, and in effect utilizes less spacefor existing production lines. Furthermore, the expense associated withoperating the ovens is no longer an issue and the result is decreasedproduction costs. For new production lines, removal of these ovens fromthe design actually saves space, and hence a smaller building may beused to house the production line, thereby decreasing the constructioncosts. In addition, the capital expenditure for the new production linewill be less because ovens are no longer required. The smaller volumeoccupied by production lines of the methods and compositions describedherein increase productivity by allowing for increased numbers ofproduction lines in comparison to solvent based processes, and allowingfor integration into established production lines.

The coating methods and compositions described herein, and theassociated coating production lines described herein, may be integratedwith an associated production line for an article of manufacture. Forinstance, with the removal of large ovens associated with thermal-cureprocesses, streamlined coating production lines may be inserted into, byway of example only, the production line for objects that are typicallycoated with hard chrome, or which would benefit from a hard chromecoating (but which, using the methods, compositions and assemblagesdescribed herein are instead coated with the environmentally friendlycoatings described herein), including, by way of example only,production lines for hydraulic rods and cylinders, aircraft jet enginecomponents, diesel cylinder liners, pneumatic struts, shock absorbers,aircraft landing gear, railroad wheel bearings and couplers, balljoints, axels, tool and die parts, molds for the plastic and rubberindustry, and the like.

As noted above, coating compositions which are solvent-based, whetherorganic solvent or aqueous based, require the use of heat to dry thecoated surfaces and thereby force the evaporation of the solvent. Largeovens are used to accomplish this process, and it can be appreciatedthat there is a large cost associated with operating these ovens.Furthermore, the use of ventilation systems (for instance large fans),and air pollution control systems all require energy to operate.Therefore, the UV-curable coatings, compositions and methods describedherein create significant energy and cost savings by limiting (oreliminating) the need for large ovens, associated ventilation systemsand air purification systems required for alternative thermal orsolvent-based coating compositions and methods.

Gloss essentially refers to the smoothness and shine of a surface, andboth of these properties are important when considering the visualappearance and ultimate visual acceptability of a coating. As discussedabove, the incorporation of polymerizable pigment dispersions into thecoating composition can yield greater tinctorial strength and enhancedgloss. Furthermore, the incorporation of fillers in the coatingcomposition, along with controlled polymerization conditions, can impartenhanced smoothness. The control of the polymerization process will bedescribed in detail later, briefly however, it involves the use ofmixtures of photoinitiators which possess different absorbancecharacteristics such that longer wavelength radiation can be used toexcite a photoinitiator or photoinitiators of the mixture, while shorterwavelength radiation is used to excite the other photoinitiators of themixture. In this manner, the order of excitation can be important. It isdesirable that the longer wavelength photoinitiators are excited first,as this allows for improved adhesion and traps the filler components inplace. The shorter wavelengths photoinitiators are then excited tocomplete the polymerization process. If this order of excitation is notused (or a variant thereof, such as alternating exposures, flashing orother sequences) the filler compounds can aggregate and create a mattedfinish. Thus, the long wavelength-short wavelength procedure can improvevisual appearance and acceptability by enhancing the surface smoothness,enhancing the surface shine, or enhancing the surface smoothness andsurface shine. However, if a matted appearance is desired, then a shortwavelength-long wavelength procedure may be used.

There is considerable benefit to having a coating composition andprocess which requires only a single coating step. This is costeffective in terms of the quantity of coating composition used, as wellas with the overall production time per item coated. The coatingcomposition must still impart beneficial qualities, such as corrosionresistance and abrasion resistance when applied as a single coat. TheUV-curable coating compositions described herein utilize fillers and/ornano-fillers, and/or slip and flow enhancers, in the mixture ofoligomers, monomers, polymerizable pigment dispersion, andphotoinitiators, to impart desirable rheological characteristics to thecomposition and the resulting film which has been applied to the surfaceprior to exposure to UV radiation. These rheological properties includeviscosity and thixotropic behavior, which allows the composition to besprayed onto a surface, allows the composition to remain where it landson the surface, and allows the composition droplets to flow together andfill in any gaps without dripping or running off the surface, therebycreating a complete, near pinhole-free film on the surface. Such controlof the rheological properties of the UV-curable coating compositiondescribed herein gives coatings with improved coverage obtained in asingle application step, and thereby, in the case of pigmentedcompositions described herein, improves the coating hiding power. Inaddition, the coating composition described herein, still impartbeneficial qualities to the resulting cured coating, such as smoothness,slickness, abrasion and scratch resistance, improved adhesion, hardness,and impact resistance, when applied as a single coat onto a variety ofmaterials such as, but not limited to, metals, fiber glass, glass,plastics, wood, paper, and ceramics.

The 100% solids,UV-curable coating compositions described herein can beapplied to surfaces by spraying, curtain coating, dipping, rolling orbrushing. However, spraying is the one of the most efficient methods ofapplication, and this can be accomplished using High Volume Low Pressure(HVLP) methodology or electrostatic spraying technology. HVLP andelectrostatic spraying techniques are methods well established in thecoating industry, thus it is adventitious to develop coatingcompositions which utilize these application means. In addition, theUV-curable compositions described herein may be applied usingair-assisted/airless type spraying technology. Air-assisted airlesspumps are usually air-operated, positive displacement, reciprocatingpiston pumps that siphon coating compositions directly out of acontainer. An air compressor operates both the pump and the gun at aboutone-quarter the amount of air needed for a conversion HVLP gun, with thefluid is delivered at a significantly higher fluid pressure. The coatingcomposition atomizes as it escapes to atmospheric pressure, and the gunthen adds a little bit of air to the ends of the spray pattern,eliminating the “tails” or heavy edges, thereby minimizing overlappinglines or stripes. Thus, the “air assist” of the “airless” process.

The cleaning regimens used to clean surfaces prior to coating withsolvent-based coating compositions generally involves contacting thesurface with an alkaline-based cleaner or an acidic cleaner, typicallyas aqueous solutions. Examples of alkaline cleaning agents includesodium hydroxide and potassium hydroxide. In addition to the cleaningagent and water, the cleaning solution may optionally includesurfactants and builders, such as soda ash, pyrophosphate, ortripolyphosphate. Thus, harsh conditions are needed to clean surfacesprior to coating with solvent-based compositions. In contrast, asdiscussed above, the methods and compositions described herein requirelimited and simple (if any) cleaning prior to coating an object. In oneembodiment, cleaning an article prior to coating with the 100% solids,UV-curable coating compositions described herein simply requires washingwith a biodegradable organic cleaner and water to remove looseimpurities, surface soils, oil and grease, a water rinse, and drying.The water rinse can use deionized, purified water or tap water, with acontact time and/or water flow rate sufficient to remove substantiallyall of the cleaner from the surface. The waste stream from thissimplified cleaning process contains less toxic and/or harmful materialsthan the process used for solvent-based coating compositions. Thus, thiscleaning process is more environmentally friendly than the process usedfor solvent-based coating compositions.

The characteristics of the UV curable, 100% solids compositionsdescribed herein include, but are not limited to, zero VOC's, zeroHAP's, cure in seconds, for example, but not limited to, 1.5 seconds,(thereby decreasing cure time by 99%), require up to 80% less floorspace, require up to 80% less energy, are non-flammable, require nothinning, are extremely durable, are high gloss, applied using HVLP orelectrostatic bell, do not require flash off ovens, do not requirethermal cure, have no thermal stress and no orange peel effect. Further,they enable the user to decrease production time while producing aproduct with superior, more reproducible appearance. The user stands tosave time, energy, and space. In addition, the user may reduce oreliminate emissions as no solvent or vehicles are used. Also, thecompositions disclosed herein produce, without the use of milling, clearor opaque coatings with improved adhesion which may be, smooth, slick,abrasion and scratch resistant, hard, or impact resistant.

Processes and assemblages for applying sprayable, ultraviolet lightcurable, 100% solids compositions described herein are disclosed.Characteristics of the processes include, but are not limited to,providing an industrial strength coating, having up to 98% reclamationof overspray, no cooling line required, immediate “pack and ship,”decreased parts in process, less workholders, no workholder burn off,eliminate air pollution control systems, safer for the environment,safer for employees, decreased production costs, decreased productiontime, and increased production.

Compositions

The mechanical properties of UV-coatings, such as elasticity,flexibility and hardness depend upon the type of oligomers and monomersincorporated into the coating composition. By way of example only,polyester acrylates combine good abrasion resistance with toughness,whereas urethane acrylates and polyether acrylates can provideflexibility, elasticity and hardness. Thus, the composition describedherein combine oligomers and monomers which impart various properties tocured coatings to obtain UV-curable coatings with good adhesion, highflexibility, and abrasion and scratch resistance.

The compositions described herein are essentially solvent free, and aretherefore referred to as a solids composition. Thus, there is disclosedcompositions of matter comprising UV-curable materials (oligomers andmonomers), photoinitiators, solid pigment dispersions, adhesionpromoters, slip and flow enhancers, corrosion inhibitors, fillers andnano-fillers to obtain flexible, and/or abrasion and scratch resistant,and/or impact resistant and/or smooth, and/or hard coatings, which alsoexhibits enhanced adhesion and/or slip properties. The compositionsdescribed herein consists of, based on total composition weight; 15-45%oligomers or multiplicity of oligomers, 25-65% of monomer ormultiplicity of monomers, 2-10% photoinitiator or multiplicity ofphotoinitiators, 0-15% solid pigment or multiplicity of solid pigmentdispersions, 0.01-2% corrosion inhibitor, 0.01-2% filler, and 0.1%-25%nano-filler mixture; wherein the composition is sprayable by HVLP,electrostatic bell, or air-assisted/airless without the addition ofheat, and is curable by ultraviolet radiation.

The oligomers may be selected from the group consisting ofmonoacrylates, diacrylates, triacrylates, polyacrylates, urethaneacrylates, polyester acrylates, polyether acrylates, epoxy acrylates andmixtures thereof. Suitable compounds which may be used include, but arenot limited to, trimethylolpropane triacrylate, alkoxylatedtrimethylolpropane triacrylate, such as ethoxylated or propoxylatedtrimethyolpropane triacrylate, 1,6-hexane diol diacrylate, isobornylacrylate, aliphatic urethane acrylates (di-, tri-, hex-: Ebecryl 230,Ebecryl 244, Ebecryl 264, Ebecryl 220), vinyl acrylates, epoxyacrylates, ethoxylated bisphenol A diacrylates, trifunctional acrylicester, unsaturated cyclic diones, polyester diacrylates; epoxydiacrylate/monomer blends, aliphatic urethane triacrylate/monomerblends, aliphatic urethane triacrylates blended with 1,6-hexanediolacrylate, hexafunctional urethane acrylates, siliconized urethaneacrylates, aliphatic siliconized urethane acrylates, CN990 (Sartomer,Exton, Pa., U.S.A.), bisphenol epoxy acrylates blended withtrimethylolpropane triacrylate, fatty acid modified bisphenol Aacrylates, acrylated epoxy polyol blended with trimethylolpropanetriacrylate, and mixtures thereof.

The monomers are chosen from a group consisting of 2-phenoxyethylacrylate, isobornyl acrylate, acrylate ester derivatives, methacrylateester derivatives; trimethylolpropane triacrylate, 2-phenoxyethylacrylate esters, and cross-linking agents, such as, but not limited to,propoxylated glyceryl triacrylate, tripropylene glycol diacrylate, andmixtures thereof.

The rapid polymerization reaction is initiated by a photoinitiatorcomponent of the composition when exposed to ultraviolet light. Thephotoinitiators used in the compositions described herein arecategorized as free radicals; however, other photoinitiator types can beused. Furthermore, combinations of photoinitiators may be used whichencompass different spectral properties of the UV sources used toinitiate polymerization. In one embodiment, the photoinitiators arematched to the spectral properties of the UV sources. It is to beappreciated that the compositions described herein may be cured bymedium pressure mercury arc lights which produce intense UV-C (200-280nm) radiation, or by doped mercury discharge lamps which produce UV-A(315-400 nm) radiation, or UV-B (280-315 nm) radiation depending on thedopant, or by combination of lamp types depending on the photoinitiatorcombinations used. In addition, the presence of pigments can absorbradiation both in the UV and visible light regions, thereby reducing theeffectiveness of some types of photoinitator. However, phosphine oxidetype photoinitiators, for example but not limited to bis acylphosphineoxide, are effective in pigmented, including, by way of example only,black, UV-curable coating materials. Phosphine oxides also find use asphotoinitiators for white coatings.

The photoinitiators and co-photoinitiators may be selected from a groupconsisting of phosphine oxide type photoinitiators,diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, benzophenone,1-hydroxycyclohexyl phenyl ketone,2-hydroxy-2-methyl-1-phenyl-propan-1-one (DAROCUR® 1173 from CibaSpecialty Chemicals 540 White Plains Road, Tarrytown, N.Y., U.S.A.)),2,4,6-trimethylbenzophenone and 4-methylbenzophenone, ESACURE® KTO-46(Lamberti S.p.A., Gallarate (VA), Italy),oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone), amineacrylates, thioxanthones, benzyl methyl ketal, and mixtures thereof. Inaddition, the photoinitiators and co-photoinitiators may be selectedfrom 2-hydroxy-2-methyl-1-phenyl-propan-1-one (DAROCUR® 1173 from CibaSpecialty Chemicals 540 White Plains Road, Tarrytown, N.Y., U.S.A.),phosphine oxide type photoinitiators, IRGACURE® 500 (Ciba SpecialtyChemicals 540 White Plains Road, Tarrytown, N.Y., U.S.A.), amineacrylates, thioxanthones, benzyl methyl ketal, and mixtures thereof. Inaddition, thioxanthone is used as a curing booster. The liquidphotoinitiator is chosen from a group consisting of benzonephenones,1-hydroxycyclohexyl phenyl ketone, phosphine oxides, and mixturesthereof. The solid photoinitiator is a phosphine oxide.

Other photoinitiators which are suitable for use in the practicedescribed herein include, but are not limited to,1-phenyl-2-hydroxy-2-methyl-1-propanone, oligo{2-hydroxy-2methyl-1-4-(methylvinyl)phenylpropanone)}, 2-hydroxy 2-methyl-1-phenylpropan-1 one, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl phosphineoxide, 1-hydroxycyclohexyl phenyl ketone and benzophenone as well asmixtures thereof. Still other useful photoinitiators include, forexample, bis(n,5,2,4-cyclopentadien-1-yl)-bis2,6-difluoro-3-(1H-pyrol-1-yl)phenyl titanium and2-benzyl-2-N,N-dimethyl amino-1-(4-morpholinophenyl)-1-butanone. Thesecompounds are IRGACURE® 784 and IRGACURE® 369, respectively (both fromCiba Specialty Chemicals 540 White Plains Road, Tarrytown, N.Y., U.S.A.)While, still other useful photoiniators include, for example,2-methyl-1-4(methylthio)-2-morpholinopropan-1-one,4-(2-hydroxy)phenyl-2-hydroxy-2-(methylpropyl)ketone, 1-hydroxycyclohexyl phenyl ketone benzophenone,(cyclopentadienyl)(1-methylethyl)benzene-iron hexafluorophosphate,2,2-dimethoxy-2-phenyl-1-acetophen-one 2,4,6-trimethyl benzoyl-diphenylphosphine oxide, benzoic acid, 4-(dimethyl amino)-ethyl ether, as wellas mixtures thereof.

Corrosion inhibitors are formulated into coatings to minimize corrosionof the substrate to which it is applied. Suitable corrosion inhibitorscan be selected from organic pigments, inorganic pigments,organometallic pigments or other organic compounds which are insolublein the aqueous phase. It is also possible to use concomitantlyanti-corrosion pigments, for example pigments containing phosphates orborates, metal pigments and metal oxide pigments, for example but notlimited to zinc phosphates, zinc borates, silicic acid or silicates, forexample calcium or strontium silicates, and also organic pigmentscorrosion inhibitor based on aminoanthraquinone. In addition inorganiccorrosion inhibitors, for example salts of nitroisophthalic acid,tannin, phosphoric esters, substituted benzotriazoles or substitutedphenols, can be used. Furthermore, sparingly water-soluble titanium orzirconium complexes of carboxylic acids and resin bound ketocarboxylicacids are particularly suitable as corrosion inhibitors in coatingcompositions for protecting metallic surfaces. In addition, anembodiment is an all-solids, non-metal corrosion inhibitor, including byway of example only, Cortec Corporation's (4119 White Bear Parkway, St.Paul, Minn., U.S.A.), M-235 product, and any other upgrades andsuperseding products.

Pigments, are insoluble white, black, or colored material, typicallysuspended in a vehicle for use in a paint or ink, and may also includeeffect pigments such as micas, metallic pigments such as aluminum, andopalescent pigments. Pigments are used in coatings to provide decorativeand/or protective functions however, due to their insolubility, pigmentsmay be a possible contributing factor to a variety of problems in liquidcoatings and/or dry paint films. Examples of some film defects thoughtto be attributable to pigments include: undesirable gloss due toaggregates, blooming, pigment fading, pigment flocculation and/orsettlement, separation of pigment mixtures, brittleness, moisturesusceptibility, fungal growth susceptibility, and/or thermalinstability.

An “ideal” dispersion consists of a homogeneous suspension of primaryparticles. However, inorganic pigments are often incompatible with theresin in which they are incorporated, and this generally results in thefailure of the pigment to uniformly disperse. Furthermore, a millingstep may be required as dry pigments comprise a mixture of primaryparticles, aggregates, and agglomerates which must be wetted andde-aggregated before the production of a stable, pigment dispersion isobtained. The level of dispersion in a particular pigment-containingcoating composition affects the application properties of thecomposition as well as the optical properties of the cured film.Improvements in dispersion result in improvements in gloss, colorstrength, brightness, and gloss retention.

Treatment of the pigment surface to incorporate reactive functionalityimproves pigment dispersion. Examples of surface modifiers include, butare not limited to, polymers such as polystyrene, polypropylene,polyesters, styrene-methacrylic acid type copolymers, styrene-acrylicacid type copolymers, polytetrafluoroethylene,polychlorotrifluoroethylene, polyethylenetetrafluoroethylene typecopolymers, polyaspartic acid, polyglutamic acid, and polyglutamicacid-γ-methyl esters, and modifiers such as silane coupling agents andalcohols.

These surface-modified pigments improve the pigment dispersion in avariety of resins, for example, olefins such as, by way of example only,polyethylene, polypropylene, polybutadiene, and the like; vinyls such aspolyvinylchloride, polyvinylesters, polystyrene; acrylic homopolymersand copolymers; phenolics; amino resins; alkyds, epoxys, siloxanes,nylons, polyurethanes, phenoxys, polycarbonates, polysulfones,polyesters (optionally chlorinated), polyethers, acetals, polyimides,and polyoxyethylenes.

Various organic pigments can be used in the compositions describedherein, including, but not limited to, carbon black, azo-pigment,phthalocyanine pigment, thioindigo pigment, anthraquinone pigment,flavanthrone pigment, indanthrene pigment, anthrapyridine pigment,pyranthrone pigment, perylene pigment, perynone pigment and quinacridonepigment.

Various inorganic pigments can be used in the compositions describedherein, for example, but not limited to, titanium dioxide, aluminumoxide, zinc oxide, zirconium oxide, iron oxides: red oxide, yellow oxideand black oxide, Ultramarine blue, Prussian blue, chromium oxide andchromium hydroxide, barium sulfate, tin oxide, calcium, titanium dioxide(rutile and anatase titanium), sulfate, talc, mica, silicas, dolomite,zinc sulfide, antimony oxide, zirconium dioxide, silicon dioxide,cadmium sulfide, cadmium selenide, lead chromate, zinc chromate, nickeltitanate, clays such as kaolin clay, muscovite and sericite.

The solid pigment dispersions used in the compositions described hereinmay also be selected from a group consisting of the following pigmentsbonded with modified acrylic resins: carbon black, rutile titaniumdioxide, organic red pigment, phthalo blue pigment, red oxide pigment,isoindoline yellow pigment, phthalo green pigment, quinacridone violet,carbazole violet, masstone black, light lemon yellow oxide, lightorganic yellow, transparent yellow oxide, diarylide orange, quinacridonered, organic scarlet, light organic red, and deep organic red. Thesepolymerizable pigment dispersions are distinguishable from other pigmentdispersions which disperse insoluble pigment particles in some type ofresin and entrap the pigment particles within a polymerized matrix. Thepigment dispersions used in the compositions and methods describedherein have pigments treated such that they are attached to acrylicresins; consequently the pigment dispersion is polymerizable uponexposure to UV irradiation and becomes intricately involved in theoverall coating properties.

The average particle size of fillers in the compositions describedherein includes by way of example less than about 20 μm, and by way offurther example, with an average particle size 1 to 10 μm discreteparticles; whereas, the average particle size of nano-filler particlesincludes by way of example less than about 200 nm, and by way of furtherexample, with an average particle size 5 to 50 nm discrete particles. tonanometer-sized particles. The addition of fillers imparts certainrheological properties to the composition, such as viscosity; however,the addition of nanoscale fillers imparts dramatically different effectson the coating mechanical properties in comparison to micron scalefillers. Thus, the mechanical properties of coatings can be manipulatedby varying the content of micron sized fillers and nano-fillers in thecoating composition.

Polymer nanocomposites are the blend of nanometer-sized fillers witheither a thermoset or UV-curable polymers, and such polymernanocomposites have improved properties compared to conventional fillermaterials. These improved properties include improved tensile strength,modulus, heat distortion temperature, barrier properties, UV resistance,abrasion and scratch resistance, and conductivity. Clear, abrasionresistant and scratch-resistant coatings are needed in a variety ofproducts, including fingernail polishes, flooring, plastic glazing,headlamp covers and other automotive parts, transportation windows andoptical lenses. The incorporation of certain nano-fillers, such asnano-alumina and nano-silicon, can provide long-term abrasion andscratch resistant coatings without significantly effecting opticalclarity, gloss, color or physical properties. These improved propertiesmay be in large part due to the small size and large surface area of thenanoscale fillers.

Fillers and nano-fillers can be either insoluble inorganic particles, orinsoluble organic particles. The inorganic fillers and nano-fillers aregenerally metal oxides, although other inorganic compounds can be used.Examples of inorganic fillers and nano-fillers include aluminumnitrides, aluminum oxides, antimony oxides, barium sulfates, bismuthoxides, cadmium selenides, cadmium sulfides, calcium sulfates, ceriumoxides, chromium oxides, copper oxides, indium tin oxides, iron oxides,lead chromates, nickel titanates, niobium oxides, rare earth oxides,silicas, silicon dioxides, silver oxides, tin oxides, titanium dioxides,zinc chromates, zinc oxides, zinc sulfides, zirconium dioxides, andzirconium oxides. Alternatively, organic fillers and nano-fillers aregenerally polymeric materials ground into appropriate sizedparticulates. Examples of nanometer sized organic nano-fillers include,but are not limited to, nano-polytetrafluoroethylene, acrylatenanosphere colloids, methacrylate nanosphere colloids, and combinationsthereof, although micron sized fillers of the polytetrafluoroethylene,acrylate, methacrylate, and combinations thereof may be used. Examplesof nano-fillers composed of a combination of inorganic and organicmaterials include any of the aforementioned inorganic nanoparticles thathave been coated, at least in part, with an organic compound.Alternatively, the aforementioned organic nanoparticles may be coatedwith an inorganic coating. Further the organic and inorganic materialsmay be otherwise intermingled.

Nano-alumina is composed of high purity aluminum oxide that is ofnanometer size, including by way of example less than 200 nm, and withinthe range of approximately 5-40 nanometer discrete spherical particles.The incorporation of nano-alumina into coating systems maintainsexcellent optical clarity, gloss and physical properties of thecoatings, such that nano-alumina-based compositions find use in abrasionresistant coating applications requiring superior optical transparencysuch as eye glasses; fine polishing applications, includingsemiconductors; and nanocomposite applications, including improvedthermal management. In addition, incorporation of nano-alumina intocoating compositions can results in extremely hard coatings, which mayreplace “hard chrome”, and find use in coating objects which may needimpact resistance.

“Hard chrome” is generally obtained from the process ofelectrodepositing a thick layer (0.2 mils to 30 mils or more) ofchromium, usually applied directly to ferrous substrates, like steel,although it can also be applied to non-ferrous substrates. The thickchrome is almost always deposited from a hexavalent chromium platingbath. “Hard chrome” can be used for the hard tipping of cutting toolsand to build up shafts or areas on steel that are subject to severewear. The chromium deposit is usually selected to take advantage of itsdesirable properties, such as hardness, wearability, corrosionresistance, lubricity, and low coefficient of friction. A variety ofparts which can be hard chrome plated include, hydraulic rods andcylinders, aircraft jet engine components, diesel cylinder liners,pneumatic struts for automobile hatchbacks, shock absorbers, aircraftlanding gear, railroad wheel bearings and couplers, tool and die parts,and molds for the plastic and rubber industry.

Chromium can exist in two valence states, trivalent chromium (Cr III)and hexavalent chromium (Cr VI). Chromium III is an essential element inhumans and is much less toxic than chromium (VI). The respiratory tractis the major target organ for chromium (VI) toxicity, for acute(short-term) and chronic (long-term) inhalation exposures. Shortness ofbreath, coughing, and wheezing can occur from acute exposure to chromium(VI), while perforations and ulcerations of the septum, bronchitis,decreased pulmonary function, pneumonia, and other respiratory effectshave been noted from chronic exposure. Human studies have clearlyestablished that inhaled chromium (VI) is a human carcinogen, resultingin an increased risk of lung cancer. It is clear that hexavalentchromium plating baths have significant health risks and environmentaltoxicity issues associated with their use to obtain hard coatings. Inaddition, the use of the hard chrome plating process can take severalhours to build up, and is therefore very time consuming. Thus, there isa need for the development of coatings which are easy and rapid toapply, are not a health risk, and are also not hazardous to theenvironment. The nano-alumina coating compositions described herein areenvironmentally friendly, can be applied easily and quickly, and resultin hard, highly abrasion resistant and scratch resistant coatings. Inaddition, the resulting coatings exhibit improved slip properties,offering an alternative to TEFLON® (polytetrafluoroethylene), coatingscomprising TEFLON®, or TEFLON® like coatings. Furthermore, theincorporation of nano-alumina into coating systems also maintainsexcellent optical clarity, gloss and physical properties of thecoatings.

Nano-silicon dioxides having a nanometer size, including by way ofexample less than about 200 nm, and by way of further example, with anaverage particle size 5 to 50 nm, can be incorporated into coatingcompositions with up to 40˜65% silica content with little increase incomposition viscosity and no loss in coating clarity. In addition, theresulting coating also has improved toughness, hardness and abrasion andscratch resistance, with no reduction in coating transparency and gloss.Other properties and features obtained when incorporating nano-siliconinto coating compositions are, it acts as a barrier effect againstgases, water vapor and solvents, it has increased weathering resistanceand inhibited thermal aging, it exhibits reduced cure shrinkage and heatof reaction, reduced thermal expansion and internal stresses, increasedtear resistance, fracture toughness and modulus, has improved adhesionto a large number of inorganic substrates (e.g. glass, aluminium), hasimproved dirt resistance against inorganic impurities (e.g. soot) by amore hydrophilic surface, and has improvements to other desiredproperties such as: thermal stability, stain-resistance, heatconductivity, dielectric properties.

Other materials having properties such as wear resistance, hardness,stiffness, abrasion resistance, chemical resistance, and corrosionresistance which may be used as nano-fillers include: oxides, carbides,nitrides, borides, silicates, ferrites and titanates. For instance,examples of such nano-fillers are, but not limited to, nano-zirconiumoxide, nano-zirconium dioxides, nano-silicon carbide, nano-siliconnitride, nano-sialon (silicon aluminum oxynitride), nano-aluminumnitrides, nano-bismuth oxides, nano-cerium oxides, nano-copper oxides,nano-iron oxides, nano-nickel titanates, nano-niobium oxides, nano-rareearth oxides, nano-silver oxides, nano-tin oxides, and nano-titaniumoxides. In addition to these properties, these materials have relativelyhigh mechanical strength at high temperatures.

Alternatively, the micron sized fillers used in the compositiondescribed herein are selected from a group consisting of amorphoussilicon dioxide prepared with polyethylene wax, synthetic amorphoussilica with organic surface treatment, untreated amorphous silicondioxide, alkyl quaternary bentonite, colloidal silica, acrylatedcolloidal silica, alumina, zirconia, zinc oxide, niobia, titaniaaluminum nitride, silver oxide, cerium oxides, and combinations thereof.The silicon dioxides are chosen from a group consisting of bothsynthetic and natural silicon dioxides with surface treatments includingpolyethylene wax or waxes and IRGANOX® from Ciba Specialty Chemicals 540White Plains Road, Tarrytown, N.Y., U.S.A.

Compositions described herein may be used to impart hard, abrasion andscratch resistant and impact resistant coatings on a variety of objects,thereby substituting for, or replacing, “hard chrome” coatings onobjects or articles of manufacture in which at least one function of theobject or article of manufacture would be enhanced or improved by thepresence of a “hard chrome” coating. Examples of such objects orarticles of manufacture which can be hard coated using compositionsdescribed herein include, but are not limited to, hydraulic rods andcylinders, aircraft jet engine components, diesel cylinder liners,pneumatic struts for automobile hatchbacks, shock absorbers, aircraftlanding gear, railroad wheel bearings and couplers, tool and die parts,and molds for the plastic and rubber industry. In addition, clear coatcompositions described herein may be used to hard coat glass, such thatimproved “shatter proof” properties are imparted to the glass.

Slip indicates the ease with which two contacting surfaces can move byeach other. Coatings are said to have good slip when they have a lowcoefficient of friction and poor slip when they have a high coefficientof friction. Coated surfaces which are tack-free and behave as if theyare lubricated have good slip characteristics, allowing coated materialsto slide by one another. Slip is an important characteristic of coatedobjects, particularly objects which benefit from minimal friction suchas, but not limited to, hydraulic rods, hydraulic cylinders, wheelbearings and shock absorbers. In addition, manufacturing processes suchas, but not limited to, forming operations, filling, handling andshipping, may also benefit from the use of coated objects with good slipproperties. To provide good substrate wetting and slip with no migrationproperties to the coated surface it is desirable to incorporate sometype of slip and flow enhancer, also referred herein as a slip and flowimprover, into the composition. Slip and flow enhancers reduce thefriction coefficient and surface tension, thereby facilitating spreadingof coating compositions and improving slip characteristics of curedcoatings. Slip and flow enhancers may be waxes, polymeric compounds,oligomers, monomers, inorganic compounds, or organic compounds. Examplesof slip and flow enhancers are, but not limited to, various waxes,silicones, modified polyesters, acrylated silicone, molybdenumdisulfide, tungsten disulfide, EBECRYL® 350 (UCB Surface Specialties,Brussels, Belgium), EBECRYL® 1360 (UCB Surface Specialties, Brussels,Belgium), and CN990 (Sartomer, Exton, Pa., U.S.A.),polytetrafluoroethylene, a combination of polyethylene wax andpolytetrafluoroethylene, dispersion of low molecular weight polyethyleneor polymeric wax, silicone oils, and the like. Slip and flow enhancerstypically comprise less than 20% by weight of a coating composition.When slip and flow enhancers are incorporated as minor components intocoating compositions, they are referred to as additives, and typically,by way of example only, comprise less than 5% by weight of a coatingcomposition. Alternatively, slip and flow enhancers may be a significantproportion of the formulation, and may be referred to as slip and flowenhancing oligomers as they are an integral component of the resultingcoating. Typically, by way of example only, slip and flow enhancingoligomers comprise greater than 10%, of a coating composition. Anexample of such a slip and flow enhancing oligomer is CN990 (Sartomer,Exton, Pa., U.S.A.). Compositions described herein may incorporate slipand flow enhancers, as additives or slip and flow enhancing oligomers,along with nano-fillers, resulting in very smooth and slick coatingswith vastly improved hardness, and abrasion and scratch resistance. Inaddition, enhanced slip properties may be obtained using nano-fillersalone.

Coatings resulting from compositions described have improved slipproperties, and therefore may be a substitute for TEFLON®(polytetrafluoroethylene), coatings comprising TEFLON®, or TEFLON® likecoatings. A variety of objects which may benefit from the improved slipproperties include, but are not limited to, hydraulic rods andcylinders, aircraft jet engine components, diesel cylinder liners,pneumatic struts for automobile hatchbacks, shock absorbers, aircraftlanding gear, railroad wheel bearings and couplers, tool and die parts,and molds for the plastic and rubber industry. The improved slipproperties may decrease the “wear and tear” on these objects, andthereby decrease maintenance and replacement costs.

Coatings resulting from the compositions of the present invention arehard and have low coefficients of friction. The low coefficients offriction may allow coated objects to move through the air or water withless friction or drag, respectively. Objects which can benefit from theimproved slip properties of the coatings resulting from the compositionsof the present invention include, but are not limited to, ship hulls,ballistics (such as, by way of example only, bullets, missiles, andtorpedoes), airplane noses and fuselages, golf balls and other sportingequipment. In addition, the compositions of the present invention may beused to coat armaments to impart hardness and slip to, or improve thehardness and slip properties of, the armaments.

Hard chrome” coatings have been used to impart hardness to a variety ofobjects; however separate coatings are needed to impart good slipproperties to these hard coated products, for example TEFLON® typecoatings. In addition, chrome coating processes are inherently notenvironmentally friendly, as they have both environmental and healthissues. The coating compositions and processes described herein, areenvironmentally friendly, and can impart hardness and slip properties ina single coating.

Coating flexibility is an important characteristic for coatings ofobjects which flex, distort, or otherwise change shape, such as, but notlimited to, various springs and the undercarriage of motor vehicles.Coating flexibility allows the coating to flex or distort withoutcracking when the object flexes, distorts or changes shape; whereascoating adhesion properties allows the coating to remain attached to theobject when the object flexes, distorts or changes shape. Thecompositions described herein may be used to obtain flexible, abrasion,scratch and/or corrosion resistant coatings with enhanced adhesioncharacteristics. The compositions described herein thereby substitutefor, or replace, flexible coatings on objects or articles of manufacturein which at least one function of the object or article of manufacturewould be enhanced or improved by the presence of a flexible coating.Examples of such objects or articles of manufacture which can be coatedusing the compositions described herein include, but are not limited to,springs and the undercarriage of motor vehicles. Examples of suchsprings which can be coated using the compositions described hereininclude, but are not limited to, leaf springs, shock absorber springs,watch springs, and bicycle seat springs.

Possible methods of applying the composition described herein includespraying, brushing, curtain coating, dipping, and rolling. To enablespraying onto a desired surface the pre-polymerization viscosity must becontrolled. This is achieved by the use of low molecular weight monomerswhich take the place of organic solvents. However, these monomers alsoparticipate and contribute to final coating properties and do notevaporate. The viscosity of the composition described herein is fromabout 2 centipoise to about 1500 centipoise; wherein a viscosity ofapproximately 500 centipoise or less at room temperature allows forcoverage in one coat with application by HVLP, air-assisted/airless, orelectrostatic bell without the addition of heat.

Use of 100% Solids, UV-curable Coating Compositions

The compositions described herein are a significant improvement as theydo not contain any water or organic solvent which must be removed beforecomplete curing is achieved. Therefore, the compositions describedherein are much less hazardous to the environment, and are economicalbecause they requires less space, less energy and less time. Inaddition, the compositions described herein can be applied in as asingle coat, and give flexible, abrasion resistant, scratch resistantand corrosion resistant coatings with enhanced adhesion properties.Therefore, use of the compositions and methods described herein to coatobjects which flex, distort, or otherwise change shape, decreasescoating time and therefore increases production.

In addition, the compositions of the invention can be applied in asingle coat, and give a hard, abrasion and scratch resistant coatingwhich may be a substitute for “hard chrome”, also, the compositions ofthe invention can be applied in a single coat, and give a hard, slick,abrasion and scratch resistant coating, which may be a substitute forpolytetrafluoroethylene and coatings comprising polytetrafluoroethylene.

FIG. 1 is a flowchart of the process used to coat flexible objectsand/or objects comprising angular features. Initially the object iseither optionally cleaned prior to coating, or is directly coated withthe coating compositions described herein. The coated object is thenoptionally packed and shipped for consumer use, industrial use,scientific use, or any other use contemplated by the end user.

FIG. 6 is a flowchart of the process used to obtain objects, such as,but not limited to products comprised of metals, fiber glass, glass,plastics, wood, paper, and ceramics, and composites thereof, with acoating with hardness properties, a coating with slip properties, or acoating with slip and hardness properties. Initially the composition forthe desired coating properties is chosen, and the object is eitheroptionally cleaned prior to coating, or is directly coated, with thechosen coating composition. The coated object is then cured by UV lightand is then optionally packed and shipped for consumer use, industrialuse, scientific use, or any other use contemplated by the end user.

To obtain the clear or opaque, hard, slick, abrasion and scratchresistant, UV-curable coating compositions described herein, thecomponents are generally mixed together in a mixing vessel using, by wayof example only, a sawtooth blade or a helical mixer. The components ofthe composition are mixed at sufficient shear until a smooth,homogeneous coating mixture is obtained. In addition, mixing can beachieved by shaking, stirring, rocking, or agitating. The desiredcompositions are prepared to specification, such as, but not limited to,clarity, opacity, color, scratch resistance, abrasion resistance, slip,hardness, adhesion and gloss. In addition, the coating contains acombination of oligomer and monomers such that necessary specificationsare obtained.

FIG. 2 is a schematic of the assemblage of processes used for coatingobjects with the UV-curable coating compositions described herein. Thefirst stage of the assemblage is an optional mounting station, in whichthe object to be coated is attached to a movable unit, by way of exampleonly, a spindle, a hook, or a baseplate. The object can be attachedusing, by way of example only, nails, screws, bolts and nuts, tape,glue, or any combination thereof. In addition, human workers can performthe task of attachment, or alternatively, robots can be used to do thesame function. Next, the mounted object is translated by an optionalmeans for moving to an Application Station. The optional means formoving can be achieved, by way of example only, conveyer belts, rails,tracks, chains, containers, bins, carts, and combinations thereof. Inaddition, the means for moving can be mounted on a wall, or a floor, ora ceiling, or any combination thereof. The Application Station is thelocation at which the desired object is coated with the necessarycoating composition. The means for applying the coating composition islocated at the Application Station. The means for applying the coatingcomposition includes, by way of example only, High Volume Low Pressure(HVLP) equipment, electrostatic spraying equipment, air-assisted/airlessspraying equipment, brushing, rolling, dipping, blade coating, curtaincoating or a combination thereof. The multiple means for applying thecoating composition can be incorporated and arranged at the ApplicationStation whereby it is ensured that top, bottom and side coverage of theobject occurs. In addition, the mounted object is optionally rotated, onat least one axis, prior to and during the application of the coatingcomposition to ensure uniform coverage. In addition, if desired masks ortemplates may be included in order to incorporate a design, logo, or thelike onto the object. The Application Station may include multiple typesof coatings, including different coating colors, as may be desired. Whenapplication of the coating composition is complete, the mounted coatedobject may continue to rotate, or may cease rotating. The ApplicationStation may also include an optional reclamation system to reclaim anyoversprayed coating composition, and whereby reclaim at least 98% ofoversprayed coating composition. This composition recycling systemallows for significant savings in the use and production of coatingcompositions, as the reclaimed composition can be applied to differentobjects in the process line.

The mounted coated object may now be translated from the ApplicationStation, by the optional means for moving, to the Irradiation Station(also referred to herein as a curing chamber), wherein curing of thecoated object occurs. The Irradiation Station is located further alongthe production line at a separate location from the Application Station.In one embodiment the Irradiation Station has a means for limitingexposure of actinic radiation to other portions of the assemblage.Multiple means are envisioned, including, but not limited to, doors,curtains, shields, and tunnels which incorporate angular or curved pathsalong the production line. The means for limiting exposure of actinicradiation of the Irradiation Station are used, such as, by way ofexample only, either closing doors, placement of shields, or closingcurtains, to protect operators from exposure to UV radiation, and toshield the Application Station to ensure that no curing occurs there.Inside the Irradiation Station there are three sets of UV lamps arrangedto ensure top, bottom and side exposure to the UV radiation. In additioneach UV lamp set contains two separate lamp types; by way of exampleonly, one mercury arc lamp and one mercury arc lamp doped with iron, toensure proper three dimensional curing. Thus, there are actually sixlamps within the Irradiation Station. Alternatively, this threedimensional curing can be achieved by using only two lamps, by way ofexample only, one mercury arc lamp and one mercury arc lamp doped withiron, with a mirror assembly arranged to ensure exposure to the UVradiation and curing of the top, bottom and sides of the coated object.Regardless of the specific approach used, location of the two lamp typeswithin the Irradiation Station is adventitious as it does not requiretransport of the coated object to separate locations for partial curingand then complete curing.

In one embodiment, after translation of the mounted coated object insidethe Irradiation Station, the doors close and the mounted coated objectis again optionally rotated. The longer wavelength lamps, by way ofexample only, mercury arc lamp doped with iron, are activated for thepartial curing stage, and then the shorter wavelength lamps, by way ofexample only, mercury arc lamp, are activated for the full cure stage.The longer wavelength lamps do not need to be completely off before theshorter wavelength lamps are turned on. Following the two curing stages,all lamps are turned off, the doors on the other side of the IrradiationStation are opened (if doors are installed on the Irradiation Station,otherwise object is otherwise provided an exit from the IrradiationStation) and the fully cured mounted object is translated, using theoptional means for moving, to an optional Removal Station. At theoptional Removal Station coated, fully cured object may be removed fromthe mounting and, either moved to a storage facility, using the optionalmeans for moving, or immediately packed and shipped. In addition, humanworkers can perform the task of removal, or alternatively, robots can beused to do the same function. No cooling is required prior to removal,as no heat is required for the application or curing steps, with allsteps occurring at ambient temperature.

FIG. 3 depicts is an illustration of the processes used, and exemplarycomponents of the UV-curable coating compositions described herein.Generally the components are mixed together in a mixing vessel using, byway of example only, a sawtooth blade or a helical mixer. The componentsof the composition are mixed at sufficient shear until a smooth,homogeneous coating mixture is obtained. In addition, mixing can beachieved by shaking, stirring; rocking, or agitating. The desiredcompositions are prepared to specification, such as, but not limited to,opacity, color, enhanced adhesion, corrosion resistance, abrasionresistance and gloss. In addition, the coating contains a combination ofoligomer and monomers such that necessary specifications are obtained.The polymerizable pigment dispersions and fillers are optional, as shownin FIG. 3, since clear coat compositions are encompassed by thecompositions described herein.

Next, as shown in FIG. 4, the compositions are applied to the surface ofa flexible object or object comprising angular features, by anapplication means, including, but not limited to HVLP,air-assisted/airless, or electrostatic bell. FIG. 4 shows thearrangement of spray heads used for coating, although other techniquescan be used such as dipping, flow, or curtain coating. As shown in FIG.4, the object is affixed to a rotating fixture, and this combination isattached to a conveyer system for transport from the coating applicationarea to the curing area. The resulting coating film is then cured, asshown FIG. 5, by using either a single UV light source, or a combinationof light sources which emit spectral frequencies that overlap therequired wavelengths needed to excite the specific photoinitiators usedin the compositions. FIG. 5 indicates the one exemplary UV lamparrangement for complete three dimensional curing. Finally, after curingis complete, the coated surface is ready for immediate handling andshipping, without the need to wait for parts to cool or for solventemissions to dissipate.

By the combination of a properly formulated 100% solids UV-curablecoating and the appropriate frequencies of light, UV radiation is ableto penetrate opaque coatings to reach the base substrate, thereby fullycuring the coating. Since this curing process is almost instantaneous,requiring (for example) an average of 1.5 seconds per light (FIG. 6),both time and energy are conserved. Curing lights used may be highpressure mercury lamps, mercury lamps doped with gallium or iron, or incombination as required. Lamps may be powered by direct application ofvoltage, by microwaves, or by radio-waves.

A coating composition is prepared using a mixture of photoinitiatorssufficient to encompass all necessary frequencies of light. These areused to work with the lights or light pairs, arranged to ensure completecure of an object. Polymerization, in particular acrylate double bondconversion and induction period, can be affected by the choice ofoligomers, photoinitiators, inhibitors, and pigments, pigmentdispersions, as well as UV lamp irradiance and spectral output. Incomparison to clear coat formulations, the presence of pigments may makecuring much more complex due to the absorption of the UV radiation bythe pigment. Thus, the use of variable wavelength UV sources, along withmatching of absorption characteristics of photoinitiators with UV sourcespectral output, allows for curing of pigmented formulations.

Light sources used for UV curing include arc lamps, such as carbon arclamps, xenon arc lamps, mercury vapor lamps, tungsten halide lamps,lasers, the sun, sunlamps, and fluorescent lamps with ultra-violet lightemitting phosphors. Medium pressure mercury and high pressure xenonlamps have various emission lines at wavelengths which are absorbed bymost commercially available photoinitiators. In addition, mercury arclamps can be doped with iron or gallium. Alternatively, lasers aremonochromatic (single wavelength) and can be used to excitephotoinitiators which absorb at wavelengths that are too weak or notavailable when using arc lamps. For instance, medium pressure mercuryarc lamps have intense emission lines at 254 nm, 265 nm, 295 nm, 301 nm,313 nm, 366 nm, 405/408 nm, 436 nm, 546 nm, and 577/579 nm. Therefore, aphotoinitiator with an absorbance maximum at 350 nm may not be aefficiently excited using a medium pressure mercury arc lamp, but couldbe efficiently initiated using a 355 nm Nd:YVO4 (Vanadate) solid-statelasers. Commercial UV/Visible light sources with varied spectral outputin the range of 250-450 nm may be used directly for curing purposes;however wavelength selection can be achieved with the use of opticalbandpass or longpass filters. Therefore, as described herein, the usercan take advantage of the optimal photoinitiator absorbancecharacteristics.

Regardless of the light source, the emission spectra of the lamp mustoverlap the absorbance spectrum of the photoinitiator. Two aspects ofthe photoinitator absorbance spectrum need to be considered. Thewavelength absorbed and the strength of absorption (molar extinctioncoefficient). By way of example only, the photoinitiators HMPP(2-hydroxy-2-methyl-1-phenyl-propan-1-one) and TPO(diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide) in DAROCUR® 4265 (fromCiba Specialty Chemicals 540 White Plains Road, Tarrytown, N.Y., U.S.A.)have absorbance peaks at 270-290 nm and 360-380 nm, while DAROCUR® 1173(from Ciba Specialty Chemicals 540 White Plains Road, Tarrytown, N.Y.,U.S.A.) have absorbance peaks at 245 nm, 280 nm, and 331 nm, whileESACURE® KTO-46 (from Lamberti S.p.A., Gallarate (VA), Italy) haveabsorbance peaks between 245 nm and 378 nm, and MMMP in IRGACURE® 907(from Ciba Specialty Chemicals 540 White Plains Road, Tarrytown, N.Y.,U.S.A.) absorbs at 350 nm and IRGACURE® 500 (which is a blend ofIRGACURE® 184 (from Ciba Specialty Chemicals 540 White Plains Road,Tarrytown, N.Y., U.S.A.) and benzophenone) absorbs between 300 nm and450 nm.

The addition of pigment to a formulation increases the opacity of theresulting coating and can affect any through curing abilities.Furthermore, the added pigment can absorb the incident curing radiationand thereby affect the performance of the photoinitiator. Thus, thecuring properties of opaque pigmented coatings can depend on the pigmentpresent, individual formulation, irradiation conditions, and substratereflection. Therefore consideration of the respective UV/Vis absorbancecharacteristics of the pigment and the photoinitiator can be used tooptimize UV curing of pigmented coatings. Generally, photoinitiatorsused for curing pigmented formulations have a higher molar extinctioncoefficient between the longer wavelengths (300 nm-450 nm) than thoseused for curing clear formulations. Although, the presence of pigmentscan absorb radiation both in the UV and visible light regions, therebyreducing absorption suitable for radiation curing, phosphine oxide typephotoinitiators, for example but not limited to bis acylphosphine oxide,are effective in pigmented, including, by way of example only, black,UV-curable coating materials. Phosphine oxides also find use asphotoinitiators for white coatings, and enable an effective through curefor the compositions described herein.

The mercury gas discharge lamp is the UV source most widely used forcuring, as it is a very efficient lamp with intense lines UV-C (200-280nm) radiation, however it has spectral emission lines in the UV-A(315-400 nm) and in the UV-B (280-513 nm) regions. The mercury pressurestrongly affects the spectral efficiency of this lamp in the UV-A, UV-Band UV-C regions. Furthermore, by adding small amounts (doping) ofsilver, gallium, indium, lead, antimony, bismuth, manganese, iron,cobalt and/or nickel to the mercury as metal iodides or bromides, themercury spectrum can be strongly changed mainly in the UV-A, but also inthe UV-B and UV-C regions. Doped gallium gives intensive lines at 403and 417 nm; whereas doping with iron raises the spectral radiant powerin the UV-A region of 358-388 nm by a factor of 2, while because of thepresence of iodides UV-B and UV-C radiation are decreased by a factor of3 to 7. As discussed above, the presence of pigments in a coatingformulation can absorb incident radiation and thereby affect theexcitation of the photoinitiator. Thus, it is desirable to tailor the UVsource used with the pigment dispersions and the photoinitiator,photoinitiator mixture or photoinitiator/co-initiator mixture used. Forinstance, by way of example only, an iron doped mercury arc lamp(emission 358-388 nm) is ideal for use with photoinitiator ESACURE®KTO-46 (from Lamberti S.p.A., Gallarate (VA), Italy) (absorbance between245 and 378 nm) or IRGACURE® 500 (absorbance between 300 and 450 nm).

Multiple lamps with a different spectral characteristics, orsufficiently different in that there is some spectral overlap, can beused to excite mixtures of photoinitiator or mixtures of photoinitatiorsand co-initiators. For instance, by way of example only, the use of airon doped mercury arc lamp (emission 358-388 nm) in combination with apure mercury arc lamp (emission 200-280 nm). The order in which theexcitation sources are applied can be adventitiously used to obtainenhanced coating characteristic, such as, by way of example only,smoothness, shine, slip, hardness, scratch resistance, adhesion,abrasion resistance and corrosion resistance. Initial exposure of thecoated surface with the longer wavelength source is beneficial, as ittraps the filler particle in place and initiates polymerization near thesurface, thereby imparting a smooth and adherent coating. Following thiswith exposure to the higher energy, shorter wavelength radiation enablesfor a fast cure of the remaining film that has been set in place by theinitial polymerization stage.

The time of exposure to each lamp type can be manipulated to enhance thecuring of the compositions described herein. One approach used forcuring of the compositions described herein used to coat surfaces offlexible objects or objects comprising angular features, is to exposethe coated surface to the longer wavelength doped mercury arc lamps fora shorter time than exposure to the shorter wavelength mercury arc lamp.However, this exposure scheme may cause the cured coatings towrinkle/crinkle. Therefore, other exposure schemes involve identicalexposure time for both the short wavelength mercury arc lamp, and thelonger wavelength doped mercury arc lamps, or alternatively the exposuretime to the longer wavelength doped mercury arc lamp can be longer thanthe time of exposure for the short wavelength mercury arc lamps.

Testing the Coated Surface

The 100% solids, UV-curable coatings described herein have excellentdurability and may be particularly suitable for surfaces which encounterphysical wearing or exposure to various weather conditions. Themechanical properties of solid coatings and the various testing methodsfor them is described in “Mechanical Properties of Solid Coatings”Encyclopedia of Analytical Chemistry, John Wiley & Sons, 2000, which isherein incorporated by reference in its entirety. The coatings,compositions and methods described herein meet and exceed therequirements for at least one of the described tests, in some instancesmore than one of these tests, and in other instances all these tests.The descriptions for the following tests are provided by way of exampleonly.

For example, the compositions and methods described herein provide animproved cured coating that exhibits improvement in at least one of thefollowing tests: scrub resistance, impact resistance, abrasionresistance, scratch resistance, hardness, corrosion resistance, flashrust resistance, higher gloss, exterior durability such as glossretention, cracking resistance, adhesion to substrates and slipproperties

Scrub resistance testing is an accelerated procedure for determining theresistance of paints to erosion caused by rubbing. Although scrubresistance tests are intended primarily for interior coatings, they aresometimes used with exterior coatings as an additional measure of filmperformance. In a typical scrub test, the coating is applied to a ScrubTest Panel at a specified film thickness, cured, and then subjected toscrubbing with a straight-line scrub tester. The scrub resistance is thenumber of scrub cycles required to remove the coating to a specified endpoint. Alternatively, the loss in weight is determined after a specifiednumber of scrub cycles as a measure of scrub resistance, withcalculation of equivalent loss in film thickness.

Impact resistance is a traditional method for evaluating the impactstrength or toughness of a coating to a falling object. The test can usea single object (dart) shape at a single drop height, while varying theweight of the dart. The dart size and the drop height are chosendepending upon the expected impact strength of the test sample. A numberof test samples are impacted to determine an appropriate starting pointfor the weight of the dart. The test specimen is clamped securely in apneumatic ring at the base of the drop tower. The mounting bracket isadjusted to the appropriate drop height, and the dart is inserted intothe bracket. The dart is released and dropped onto the center of thetest specimen. A series of 20 to 25 impacts are conducted, and if a testspecimen passes, the drop weight is increased by one unit. If a testspecimen fails, the drop weight is decreased by one unit. Alternatively,panels are tested using progressively increasing drop heights in orderto determine the minimum drop height that gives rise to any cracking orpeeling from the substrate. The results from these impacts are used tocalculate the Impact Failure Weight—the point at which 50% of the testspecimens will fail under the impact. Typically the dart is a roundedobject with a diameter ranging from 38 mm (1.5 inches) to 51 mm (2inches) and is dropped from about 0.66 meters (26 inches) 1.5 meters (60inches).

For coatings to perform satisfactorily, they must adhere to thesubstrates on which they are applied. A variety of methods can be usedto determine how well a coating is adheres to a surface. Commonly usedevaluation techniques are performed using a knife or a pull-off adhesiontester. The knife test is a simple test requiring the use of a utilityknife to pick at the coating. It establishes whether the adhesion of acoating to a substrate, or to another coating (in multi-coat systems),is at a generally adequate level. Performance is based on both thedegree of difficulty to remove the coating from the substrate and thesize of removed coating. Alternatively, an “X” is cut into the coatingdown to the surface, using the knife and cutting guide, by making twocuts at a 30-45 degree angle which intersects to form the “X” shape. Atthe vertex, the point of the knife is used to attempt to lift up thecoating from the substrate or from the coating below.

A more formal version of the knife test is the tape test, which can beconducted with or without humidity. Incorporation of humidity to thetape adhesion/peel back test determines how the adhesive properties ofthe coating behave under conditions in which corrosion may occur.Pressure sensitive tape is applied and removed over cuts made in thecoating. There are two variants of this test; the X-cut tape test andthe cross hatch tape test. The X-cut tape test uses a sharp razor blade,scalpel, knife or other cutting device, to make two cuts into thecoating down to the substrate with a 30-45 degree angle which intersectsto form an “X”. A straightedge is used to ensure straight cuts are made.Tape is placed on the center of the intersection of the cuts and thenremoved rapidly. The X-cut area is then inspected for removal of coatingfrom the substrate or previous coating and rated. Alternatively, thecross hatch tape test is primarily intended for testing coatings lessthan 5 mils (125 microns) thick. It uses a cross-hatch pattern ratherthan the X pattern. The cross-hatch pattern is obtained by using acutting guide or a special cross-hatch cutter with multiple presetblades to make sure the incisions are properly spaced and parallel. Tapeis then applied and pulled off; the cut area is then inspected andrated. In one embodiment, a composition described herein yields acoating which is flexible, corrosion resistant, abrasion resistant andscratch resistant coating with 99+% adhesion after 10 days at 110 F in100% humidity, and/or a 180 degree bend around a mandrel, such as, byway of example only, a half inch mandrel.

A more quantitative test for adhesion is the pull-off test where aloading fixture, commonly called a dolly or stub, is affixed by anadhesive to a coating. By use of a portable pull-off adhesion tester, aload is increasingly applied to the surface until the dolly is pulledoff. The force required to pull the dolly off, or the force the dollywithstood, yields the tensile strength in pounds per square inch (psi)or mega Pascals (MPa). Failure will occur along the weakest plane withinthe system comprised of the dolly, adhesive, coating system, andsubstrate, and will be exposed by the fracture surface. This test methodmaximizes tensile stress as compared to the shear stress applied byother methods, such as scrape or knife adhesion, and results may not becomparable. The scrape test is typically limited to testing on smooth,flat surfaces. Adhesion is determined by pushing the coated surfacesbeneath a rounded stylus or loop that is loaded in increasing amountsuntil the coating is removed from the substrate surface.

Adhesion is also a measurable result of some hardness tests made bypencil hardness, gravelometer, impact (falling object, etc.) or mandrelbend as indicated by chipping off of the coating. Finally, loss ofadhesion can be noted during some chemical resistance tests where thecoating blisters, bubbles up or even falls off.

Abrasion resistance can be determined by air-blasting silicon carbidegrains, known as the ablative, at the coated test panel at a flow rateof approximately 45 g/min. The ablating continues until the coating isworn through, and the quantity of ablative used to reach break throughis determined. The abrasion resistance is designated as the grams ofablative per 25.4 μm film thickness. A similar test involves dropping asilica or silicon carbide abrasive through a tube from a specifiedheight onto a coated planar surface using gravity flow. Silica (sand) isa milder abrasive than silicon carbide and its slower rate of abrasioncan be used to differentiate between different coatings. The fallingsand test uses gravity flow rather than forced air flow and results inthe slower rate of ablation. The abrasion resistance for the fallingsand test is designated as the volume (liters) of sand per mil (25.4 μm)film thickness. In one embodiment, the compositions described hereinyield a coating with a falling sand abrasion resistance greater than 100liters/mil.

Scratch resistance testing is a comprehensive method of quantifying theadhesion properties of a wide range of coatings. The technique involvesgenerating a controlled scratch with a diamond tip on the sample undertest. The tip, either a diamond or a sharp metal tip, is drawn acrossthe coated surface under either a constant or progressive load. At acertain critical load the coating will start to fail. The critical loadscan be detected very precisely by means of an acoustic sensor attachedto the indenter holder, the frictional force and by optical microscopy.Once known the critical loads are used to quantify the adhesiveproperties of different films/substrate combinations and theseparameters constitute a unique signature of the coating system undertest.

The pencil hardness test method is a procedure for rapid, inexpensivedetermination of the film hardness of an organic coating on a substrateby pushing pencil leads of known hardness across a coated test panel.Grading pencils come in an assortment of both hard and soft, ranging inhardness from 9 H to 9 B. The ‘H’ stands for hardness, the ‘B’ standsfor blackness, and HB is for hard and black pencils. The hardest pencilis a 9 H, followed by 8 H, 7 H, 6 H, 5 H, 4 H, 3 H, 2 H, and H. Themiddle of the hardness scale is F; then HB, B, 2 B, 3 B, 4 B, 5 B, 6 B,7 B, 8 B, and 9 B, which is the softest. The hardness of some coatingsis such that a 9 H pencil will not scratch them; however these coatingsstill receive a 9 H rating to designate their hardness. In the pencilhardness test method a coated test panel is placed on a firm horizontalsurface and the pencil, held at a 45° angle, is pushed away from theoperator in a ¼ inch (6.5 mm) stroke. The process is started with thehardest pencil and continued down the scale of hardness to either of twoend points; one, the pencil that will not cut into or gouge the film(pencil hardness), or two, the pencil that will not scratch the film(scratch hardness). In one embodiment, the compositions described hereinyield a coating with a pencil hardness in the range of 6 H to 9 H.

There are a variety of corrosion resistance requirements which aneffective coating must fulfill. The corrosion resistance testingevaluations include: salt spray, scab, and cycle corrosion evaluationsand any associated creepback. The testing method for evaluating saltspray corrosion involves mounting the test panels in atemperature-controlled chamber, and then spraying the test panel with anaqueous solution of salt or salt mixtures in the form of a fine aerosol.Typically, the solution is a 5% salt (sodium chloride) solution,although the methods can vary according to chamber temperature and thecomposition of the salt solution. The test panels are inserted into thechamber and the salt solution is sprayed as a very fine fog mist overthe samples at a constant temperature. Since the spray is continual, thesamples are constantly wet, and thus, constantly subject to corrosion.The samples may be rotated frequently to ensure uniform exposure to thesalt spray mist. Test duration can be from 24 to 480 hours, or longer.Enhanced corrosion resistance may be evidenced by exposure of a testpanel for at least 400 hours without developing any significant evidenceof under-film corrosion, such as blistering or other changes inappearance which may result from pin holes in the coating. In general,the maximum allowable creepback is 2-4 mm along with at least less than10% of the surface being corroded within 2-4 mm of sharp edges. A morerigorous test involves exposure for at least 900 hours withoutdeveloping any significant evidence of under-film corrosion, such asblistering or other changes in appearance, with the maximum allowablecreepback being 2-4 mm and at least less than 10% of the surface beingcorroded within 2-4 mm of sharp edges.

Scab corrosion testing involves the use of the salt spray procedurehowever the test panel is scribed such that a scratch is created in thecoating. Scab-like corrosion then occurs along the scratch in a coatingand manifests itself as a blister like appearance emanating away fromthe scratch. Enhanced corrosion resistance for scab corrosion may bedemonstrated in that after 1 week the test panel exhibits no blisteringor surface corrosion, or other change in appearance, with is a maximumcreepback of up to 2 mm, and at least less than 10% of the surface iscorroded within 3 mm of sharp edges. A more rigorous test involvesexposure of a scribed test panel for up to 2 weeks without showingevidence of scab corrosion.

Evaluation of coated surfaces using procedures that involve continualexposure to moisture (as occurs in the salt spray test) may not emulaterealistic conditions experienced by the coated surface, which in realitywill experience periods of wet and dry environments. Thereforeevaluation of a coating using wet/dry cycles, with and without saltspray during the wet cycle, is a more realistic evaluation for daily useof a coating. The continual wetness during the salt spray test does notallow this passive oxide layer to develop.

A “cure” test is used to evaluate completeness of curing, the coatingadhesion strength to the surface, and solvent resistance. The procedureused is to take a test panel, coat it with the test sample and then cureaccording using the cure method of choice, such as actinic radiation.The coated and cured test panel is then subject to rubbing to evaluatethe number of rubs needed to expose the surface. Failure normally isdetermined by a breakthrough to the substrate surface. Generally, thecloth used to rub the surface is also soaked in an organic solvent suchas methyl ethyl ketone (MEK) as a means to accelerate testing conditionsand test for stability to solvent exposure. One rub is considered to beone back and forth cycle, and highly solvent resistant coating achieve arating of more than 100 double rubs. In addition, a secondary readingfor the cure test may also be obtained by determining at what point amarring of the surface occurs.

For evaluation of the heat resistance of a coating, a coated test panelis placed in an oven and evaluated for loss of adhesion, cracking,crazing, fading, hazing, or fogging after various periods of thermalexposure. The types of ovens used include, but are not limited to,convection ovens. The UV-curable, corrosion resistant coating describedherein may meet or exceed requirements for heat resistance with no lossof adhesion and no cracking, crazing, fading, hazing, or fogging afterleast 1 hour held at, at least 210° C., and at least 10 hrs held at, atleast 210° C.

Along with corrosion testing, a coating undergoes a number of otherevaluation criteria, resistance to chipping evaluation, and thermalshock testing. Resistance to chipping testing is primarily used tosimulate the effects of the impact of flying debris on the coating of asurface. Typically a Gravelometer, which has been designed to evaluatethe resistance of surface coatings (paint, clear coats, metallicplating, etc.) to chipping caused by the impacts of gravel or otherflying objects. In general, the test sample is mounted in the back ofthe Gravelometer, and air pressure is used to hurl approximately 300pieces of gravel, hexagonal metal nuts, or other angled objects at thetest panel. The test sample is then removed, gently wiped with a cleancloth, and then tape is applied to the entire tested surface. Removal ofthe tape then pulls off any loose fragments of the coating. Theappearance of the tested sample is then compared to standards todetermine the chipping ratings, or visual examination can also be used.Chipping ratings consist of a number which designates the number ofchips observed.

Thermal shock testing is the most strenuous temperature test, designedto show how the product will perform as it expands and contracts underextreme conditions. Thermal shock testing creates an environment thatwill show in a short period of time how a coating would behave underadverse conditions throughout years of change. Several variants oftesting include the resiliency of a coating to rapidly changingtemperatures, such as that experienced in winter when moving from a warmenvironment, such as a house, garage or warehouse, into the freezing,cold environment outside, or vice versa. Such thermal shock tests have arapid thermal ramp rate (30° C. per minute) and can be either air-to-airor liquid-to-liquid shock tests. Thermal Shock Testing is at the moresevere end on the scale of temperature tests and is used for testingcoatings, packaging, aircraft parts, military hardware or electronicsdestined to rugged duty. Most test items undergo air-to-air thermalshock testing where the test product moves from one extreme atmospherictemperature to another via mechanical means. Fully enclosed thermalshock test chambers can be used to avoid unintended exposure to ambienttemperature, whereby minimizing the thermal shock. In Thermal Shocktesting the cold zone of the chamber can be maintained at −54° C. (−65°F.) and the hot zone can be set for 160° C. (320° F.). The test panelsis held at each stage for at least an hour and then moved back and forthbetween stages in a large number of cycles. The number of Thermal Shockcycles can vary from 10 or 20 cycles, up to 1500 cycles. The UV-curable,corrosion resistant coating described herein may meet and exceed theThermal Shock testing requirement in which no loss of adhesion,cracking, crazing, fading, hazing, or fogging is observed for up to 20cycles.

Other mechanical properties of the coating which may be tested includetensile strength, flexibility, cupping, and elongation at failure.

Flexibility testing methods are used to assess the resistance of acoating to cracking and/or detachment from a flexible substrate when acoated substrate is bent. Flexibility is usually measured by a mandrelbend test or a T-bend test. The mandrel bend test involves bending acoated substrate, usually sheet metal or rubber-type materials, overeither a conical mandrel or over cylindrical mandrels of variousdiameters. The standard, smooth-steel, conical mandrel has a length of203 mm (8 in) and a diameter of 3 mm (0.125 in) at one end and 38 mm(1.5 in) at the other end. The coated substrate, coating side up, isbent around the mandrel with a lever device and the extent of cracking,if it exists, is determined. The distance from the small end of themandrel to the crack is determined visually and can be used graphicallyto determine the percent elongation. (However, there is no indication inthe test method that elongation determined from tensile studies willyield a value related to the cracking-failure point.) The mandreldiameter at the point where cracking ceases is reported as theresistance to cracking resistance or flexibility. The cylindricalmandrel test is a pass/fail test that involves placing the coatedsubstrate over a mandrel, coating side up, and bending the specimenabout 180° around the mandrel by hand at a uniform velocity in aspecified time. Usually six mandrels having diameters ranging from 25 mm(1.0 in) to 3.2 mm (0.125 in) are used. The panel is bent over thelargest diameter mandrel and then immediately examined for cracking. Ifnone occurs, the next smaller mandrel is used and so on until failureoccurs or the smallest diameter mandrel has been passed. The smallestdiameter at which cracking does not occur is reported. The test can beused to calculate coating elongation.

The T-bend test involves placing a coated metal panel with a 50 mm (2in) minimum width in a smooth jaw bench vise and holding it firmly. Thepanel must be sufficiently long that the needed number of bends can bemade, i.e. about 150 mm (6 in). Then the panel is bent 90° with thecoating on the outside of the bend, removed, and further bent by handuntil the bent end can be inserted in the vise; the vise is tightened tocomplete the 180° bend. The apex end of the bend should be as flat aspossible. This is termed a 0T (zero-T) bend. The bend is then examinedwith a 5 to 10 power magnifier for cracks and pressure-sensitive tape isapplied and removed to determine if coating can be picked off. Theprocess is then repeated by placing the bent end in the vise and bendingthrough 180° around the 0T bend, forming the 1T bend. This is continuedfor 2T, 3T, etc. bends. The lowest T bend at which no cracks are visibleand there is no pick off of coating is the value reported. Note that theradius of curvature of the bend increases with each succeeding bend andcoating elongation required to make the bend decreases with eachsucceeding bend. In one embodiment, a composition described hereinyields a coating with a flexibility up to about 2T.

Cupping tests are carried out on coatings applied to flexiblesubstrates. Cupping is potentially a more severe test than the mandrelbend test. In the cupping test, deformation of the panel can be taken tothe point where the metal fractures, which does not normally happenduring mandrel tests. The method involves sandwiching a coated metalpanel is between a hemispherical die and a hemispherical indenter.Pressure is applied to the indenter so as to form a dome shape in thepanel with the coating on the convex side. The pressure is increasedeither to a specified depth or until the coating cracks and/or detachesfrom the substrate.

Tensile strength, which is the resistance of a material to a forcetending to tear it apart and is measured as the maximum tension thematerial can withstand without tearing. The tensile strength isgenerally measured on detached coatings, but can be evaluated on coatedsubstrates. A tensile tester usually incorporates a highly sensitiveelectronic load weighing system with load cells employing strain gaugesto detect the load applied to the specimen under test. The test specimenis clamped between two grips one of which is attached to a load cell ina moving crosshead, while the other grip is fixed to the base of thetester. The crosshead is attached to two vertically mounted screws whichare rotated using a synchronous motor-gearbox assembly. The load appliedto the test specimen and the distance traveled by the crosshead are bothdisplayed on a chart recorder.

Elongation is the deformation that results from the application of atensile force and is calculated as the change in length divided by theoriginal length. Elongation is a measurement used to determine how far apiece of film will stretch before it breaks. This information useful indeveloping a coating to stretch around a corner of a piece of wood, apiece of metal that will be formed into a V-shaped object or must bebent 360° around a bottle, pipe or piece of thread without cracking. Thetest method involves conditioning a detached test film under specifiedtemperature and humidity conditions, and then cutting the test specimensinto known dimensions. A specimen is then clamped between two grips andelongated until it ruptures. The rate of elongation may vary frombetween 5 and 100 percent per minute.

Slip is determined by measuring the frictional properties of coatings.Friction is the force between surfaces that opposes sliding motion. Itis the characteristic that determines the resistance to slip or themagnitude of slip. One method to determine the static friction of acoating is to use an inclined plane sliding test or a horizontal pulltest. In the inclined plane test a coated test panel is attached to aflat, movable surface and one or more weighted sleds are individuallyplaced on the coated surface. The movable surface is raised at anincline at 1.5±0.5° s⁻¹ until the sled begins to slide down the inclinedcoated surface. The tangent of the angle of inclination at this point isreported as the static friction value, with the smaller the angle thegreater the slip characteristics of a coating. In the horizontal pullthe coated surface remains horizontal and the sled is mechanicallypulled across the coated test panel. The force required to start thesled moving is obtained and the static friction is determined bydividing this force by the sled mass. Therefore, coatings with good slipproperties have small measured forces. In one embodiment, thecompositions of the present invention yield a coating with a staticfriction in the range of 0.02 to 0.1.

EXAMPLES Example 1 Formulation for Clear Coat Composition

An embodiment for a clear coat composition to yield flexible coatingswith excellent abrasion resistance, scratch resistance, corrosionresistance and adhesion properties is prepared by mixing, with a helicalmixer, 25.683% of an aliphatic urethane triacrylate (EBECRYL® 264, fromUCB Surface Specialties, Brussels, Belgium), 18.032% 2-phenoxyethylacrylate, 26.229% isobornyl acrylate, 8.743% methacrylate esterderivative adhesion promoter (EBECRYL® 168, from UCB SurfaceSpecialties, Brussels, Belgium), 14.210% of propoxylated glyceryltriacrylate-nano-silica (Nanocryl® C-155, formerly Nanocryl® XP 21 0953,from hanse chemie AG, Geesthacht, Germany), 5.464% of DARACUR® 1173(from Ciba Specialty Chemicals 540 White Plains Road, Tarrytown, N.Y.,U.S.A.), and 1.639% of ESACURE® KTO-46 (from Lamberti S.p.A., Gallarate(VA), Italy). These components are thoroughly mixed by the helical mixeruntil a smooth composition is produced. This composition is applied byHVLP and cured by UV light.

Example 2 Formulation for Black Pigmented Composition

An embodiment for a pigmented composition to yield flexible coatingswith excellent abrasion resistance, scratch resistance, corrosionresistance and adhesion properties is prepared by mixing, with a helicalmixer, 94.43% of the clear coat composition of Example 1, with 3.60%carbon black bonded to a modified acrylic (solid pigment dispersions, PC9317 from Elementis, Staines, UK), and 2.06% synthetic amorphous silicawith organic surface treatment (SYLOID® RAD 221, from the Grace Davisondivision of WR Grace & Co., Columbia, Md., U.S.A.), to 94.34% of theclear coat composition described above. These additions are dispersedthroughout the clear coating by a helical mixer until a smooth blackcoating composition is produced which may be applied by HVLP and curedby UV light.

Example 3 Procedure Used for Making Clear Flexible Coatings WithImproved Abrasion Resistance, Scratch Resistance, Corrosion Resistance,and Adhesion Properties

A further embodiment is the procedure used for making a clear coatcomposition. The components of the coatings composition are mixed underair, as the presence of oxygen prevents premature polymerization. It isdesired that exposure light be kept to a minimum, in particularly theuse of sodium vapor lights should be avoided. However, the use ofdarkroom lighting may be an option. The components used in themanufacture of the coating composition which come in contact withmonomers and coating mixture, such as mixing vessels and mixing blades,should be made of stainless steel or plastic, preferably polyethylene orpolypropylene. Polystyrene and PVC should be avoided, as the monomersand coating mixture will dissolve them. In addition, contact of themonomers and coating mixture with mild steel, alloys of copper, acids,bases, and oxidizers should be avoided. Furthermore, brass fittings mustbe avoided, as they will cause premature polymerization or gelling. Forthe manufacture of clear coatings it is only essential to obtainthorough mixing, and consequently the control of shear is not necessary.Adequate mixing of the clear coating composition can be obtained after1-3 hours using a ⅓ horse power (hp) mixer and a 50 gallon cylindricaltank. Smaller quantities, up to 5 gallons, can be adequately mixed after3 hours using a laboratory mixer ( 1/15- 1/10 hp). Round walled vesselsare desired as this avoids accumulation of solid oligomer in corners andany subsequent problems associated with incomplete mixing. Another,parameter is that the mixers blades should be placed off of the bottomof the mixing vessel, at a distance of one half of the diameter of themixer. The oligomers are added to the mixing vessel first, and ifnecessary the oligomers are gently warmed to aid in handling. Oligomersshould not be heated over 120° F., therefore if warming is needed theuse of a temperature controlled heating oven or heating mantle isrecommended. Band heaters should be avoided. Monomers and colloidalsuspensions are added next, in any order, followed by the ester/monomeradhesion promoters. Photoinitiators are added last to ensure that thetime the complete composition is exposed to light is minimized. With themixing vessel shielded from light exposure the mixing is then carriedout after all the components are added. After mixing, there are airbubbles present and the coating may appear cloudy. These bubbles rapidlydissipate, leaving a clear coating composition. As a final step, priorto removing the coating composition from the mixing vessel, the bottomof the mixing vessel is scraped to see if any un-dissolved oligomer ispresent. This is done as a precaution to ensure thorough mixing hastaken place. If the composition is thoroughly mixed then the coatingcomposition is filtered through a 1 micron filter using a bag filter.The composition is then ready for use.

Example 4 Procedure Used for Making Pigmented Flexible Coatings WithImproved Abrasion Resistance, Scratch Resistance, Corrosion Resistance,and Adhesion Properties

A further embodiment is the manufacture procedure for pigmentedcoatings. Here a mixer of sufficient power and configuration is used tocreate laminar flow and efficiently bring the pigment dispersionsagainst the blades of the mixer. For small laboratory quantities below400 mLs, a laboratory mixer or blender is sufficient, however forquantities of up to half of a gallon a 1/15- 1/10 hp laboratory mixercan be used, but mixing will take several days. For commercialquantities, a helical or saw-tooth mixer of at least 30 hp with a 250gallon round walled, conical bottomed tank may be used. To make apigmented composition a clear coating composition is mixed first, seeExample 4. The pigment dispersion mixtures are premixed prior toaddition to the clear coat composition as this ensures obtaining thecorrect color. The premixing of the pigments dispersions is easilyachieved by shaking the pigments dispersion in a closed container, whilewearing a dust mask. The fillers, the premixed pigments/pigmentdispersions, and solid photoinitiator are then added to the clear coatcomposition and mixed for 1½ to 2 hours. Completeness of mixing isdetermined by performing a drawdown and checking for un-dissolvedpigment. This is accomplished by drawing off a small quantity of thepigmented mixture from the bottom of the mixing tank and applying a thincoating onto a surface. This thin coating is then examined for thepresence of any pigment which had not dissolved. The mixture is then runthrough a 100 mesh filter. A thoroughly mixed pigmented coatingcomposition will show little or no un-dissolved pigment.

Example 5 Process for Coating the External Surface of Leaf Springs WithClear Flexible Coatings With Improved Abrasion Resistance, ScratchResistance, Corrosion Resistance, and Adhesion Properties

Still another embodiment is the process for coating the external surfaceof leaf springs with an actinic radiation curable, substantially allsolids composition as described in example 1. The process begins byattaching a leaf spring to a rotatable spindle, and then attaching thiscombination to a conveyer belt system. The leaf spring may bepre-cleaned using a biodegradable organic cleaner at a separate CleaningStation or the leaf spring may be pre-cleaned prior to attachment ontothe rotatable spindle. Note that rotation of the rotatable spindle/leafspring assembly during the coating procedure ensures a complete coatingof the leaf spring surface. The rotatable spindle/leaf spring assemblyis then moved via the conveyer belt system into the coating applicationsection, locating the rotatable spindle/leaf spring assembly in thevicinity of electrostatic spraying system. The electrostatic sprayingsystem has three spray heads arranged to ensure top, bottom and sidecoverage of the object being coated. Rotation of the spindle/leaf springassembly begins prior to spraying of the coating composition from thethree spray heads. The coating composition is then appliedsimultaneously from the three electrostatic spray heads, while thespindle/leaf spring assembly continues to rotate. The coatedspindle/leaf spring assembly is then transported by the conveyer beltinto a curing chamber located further down the process line. The curingchamber has two sets of doors which are closed during curing to protectoperators form exposure to UV radiation. Inside the curing chamber thethree sets of UV lamps are arranged to ensure top, bottom and sideexposure to the UV radiation. Furthermore each UV lamp set contains twoseparate lamp types; one a mercury arc lamp and the other a mercury arclamp doped with iron, to ensure proper curing. Therefore there areactually six lamps with in the curing chamber. Note that this threedimensional curing can be achieved by using only two lamps, one amercury arc lamp and the other a mercury arc lamp doped with iron, witha mirror assembly to ensure exposure to the top, bottom and sides. Onceinside the curing chamber the doors close and the spindle/leaf springassembly is again rotated. The mercury arc lamp doped with iron is thenactivated for the partial curing stage, and then the mercury arc lamp isactivated for full cure. Note that the mercury arc lamp doped with irondoes not need to be completely off before the mercury arc lamp is turnedon, and the time of exposure to the doped mercury arc lamp is less thanthe time of exposure to the pure mercury arc lamp. Both lamps are turnedoff and rotation of the spindle/leaf spring assembly is stopped. Thedoors on the other side of the curing chamber are opened and the fullycured leaf spring with a clear, flexible, adherent, abrasion resistant,scratch resistant, and corrosion resistant coating is then moved via theconveyer belt to a packaging area away from the curing chamber. The leafspring is then removed from the rotatable spindle, packed and shipped.

Example 6 Process for Coating the External Surface of Leaf Springs Witha Pigmented, Flexible Coatings With Improved Abrasion Resistance,Scratch Resistance, Corrosion Resistance, and Adhesion Properties

Still another embodiment is the process for coating the external surfaceof leaf springs with an actinic radiation curable, substantially allsolids composition as described in example 2. The process begins byattaching a leaf spring to a rotatable spindle, and then attaching thiscombination to a conveyer belt system. The leaf spring may bepre-cleaned using a biodegradable organic cleaner at a separate CleaningStation or the leaf spring may be pre-cleaned prior to attachment ontothe rotatable spindle. Note that rotation of the rotatable spindle/leafspring assembly during the coating procedure ensures a complete coatingof the leaf spring surface. The rotatable spindle/leaf spring assemblyis then moved via the conveyer belt system into the coating applicationsection, locating the rotatable spindle/leaf spring assembly in thevicinity of electrostatic spraying system. The electrostatic sprayingsystem has three spray heads arranged to ensure top, bottom and sidecoverage of the object being coated. Rotation of the spindle/leaf springassembly begins prior to spraying of the coating composition from thethree spray heads. The coating composition is then appliedsimultaneously from the three electrostatic spray heads, while thespindle/leaf spring assembly continues to rotate. The coatedspindle/leaf spring assembly is then transported by the conveyer beltinto a curing chamber located further down the process line. The curingchamber has two sets of doors which are closed during curing to protectoperators form exposure to UV radiation. Inside the curing chamber thethree sets of UV lamps are arranged to ensure top, bottom and sideexposure to the UV radiation. Furthermore each UV lamp set contains twoseparate lamp types; one a mercury arc lamp and the other a mercury arclamp doped with iron, to ensure proper curing. Therefore there areactually six lamps with in the curing chamber. Note that this threedimensional curing can be achieved by using only two lamps, one amercury arc lamp and the other a mercury arc lamp doped with iron, witha mirror assembly to ensure exposure to the top, bottom and sides. Onceinside the curing chamber the doors close and the spindle/leaf springassembly is again rotated. The mercury arc lamp doped with iron is thenactivated for the partial curing stage, and then the mercury arc lamp isactivated for full cure. Note that the mercury arc lamp doped with irondoes not need to be completely off before the mercury arc lamp is turnedon, and the time of exposure to the doped mercury arc lamp is less thanthe time of exposure to the pure mercury arc lamp. Both lamps are turnedoff and rotation of the spindle/leaf spring assembly is stopped. Thedoors on the other side of the curing chamber are opened and the fullycured leaf spring with a black, flexible, adherent, abrasion resistant,scratch resistant, and corrosion resistant coating is then moved via theconveyer belt to a packaging area away from the curing chamber. The leafspring is then removed from the rotatable spindle, packed and shipped.

Example 7 Adhesion Testing of Pigmented, Flexible Coatings With ImprovedAbrasion Resistance, Scratch Resistance, Corrosion Resistance, andAdhesion Properties

A further embodiment is testing the adhesion stability of the curedcoating on a leaf spring, coated as described in Example 6, obtainedfrom the UV-curable coating composition described in Example 2. Theadhesion is evaluated after maintaining the coated leaf spring at 110 Fin 100% humidity for 10 days. The adhesion test is conducted using across-hatched adhesion test, wherein the cross hatch tape test uses across-hatch pattern obtained from a special cross-hatch cutter withmultiple preset blades to ensure the incisions are properly spaced andparallel. The cuts are made through the coating down to the underlyingsurface. Pressure sensitive tape is applied and removed over the cutsmade in the coating, and the tape is then pulled off the cut area andinspected for any removed coating. The coating obtained from thecomposition described in example 2 shows 99+% adhesion after 10 days at110 F in 100% humidity.

All percentages given are by weight. EBECRYLs® are available from UCBSurface Specialties, Brussels, Belgium. SYLOIDs® are available from theGrace Davison division of WR Grace & Co., Columbia, Md., U.S.A. Citedsolid pigment dispersions are available from Elementis, Staines, UK.DAROCUR® photoinitiators are available ® from Ciba Specialty Chemicals540 White Plains Road, Tarrytown, N.Y., U.S.A. ESACUREs® are availablefrom Lamberti S.p.A., Gallarate (VA) Italy. Nanocryls® are availablefrom hanse chemie AG, Geesthacht, Germany).

Example 8 Formulation for Clear Hard Chrome Substitute With SlipProperties

An embodiment for a clear coat composition to yield hard coatings withexcellent slip properties is prepared by mixing, with a helical mixer,23.941% hexafunctional urethane acrylate (EBECRYL® 8301, from UCBSurface Specialties, Brussels, Belgium), 7.366% propoxylated glyceraltriacrylate, 13.812% siliconized Urethane Acrylate (CN990 available fromSartomer, Exton, PA,), 37.753% isobornyl acrylate, 9.669% methacrylateester derivative adhesion promoter (EBECRYL® 168, from UCB SurfaceSpecialties, Brussels, Belgium), 0.092% M-235 corrosion inhibitor,2.762% nano-alumina in tripropylene glycol diacrylate (Nanobyk™ 3601available from Nanophase Technologies Corporation 1319 Marquette Drive,Romeoville, Ill.), and 4.605% IRGACURE® 500 (from Ciba SpecialtyChemicals 540 White Plains Road, Tarrytown, N.Y., U.S.A.). Thesecomponents are thoroughly mixed by the helical mixer until a smoothcomposition is produced. This composition is applied by HVLP and curedby UV light.

Example 9 Formulation for Pigmented (Grey) Hard Chrome Substitute WithSlip Properties

An embodiment for a pigmented composition to yield hard coatings withexcellent slip properties is prepared by mixing together, with a helicalmixer, 23.941% hexafunctional urethane acrylate (EBECRYL® 8301, from UCBSurface Specialties, Brussels, Belgium), 7.366% propoxylated glyceraltriacrylate, 13.812% siliconized Urethane Acrylate (CN990 available fromSartomer, Exton, Pa.,), 37.753% isobornyl acrylate, 9.669% methacrylateester derivative adhesion promoter (EBECRYL® 168, from UCB SurfaceSpecialties, Brussels, Belgium), 0.092% M-235 corrosion inhibitor,2.762% nano-alumina in tripropylene glycol diacrylate (Nanobyk™ 3601available from Nanophase Technologies Corporation 1319 Marquette Drive,Romeoville, Ill.), 9.4% gray pigment dispersion mix, 0.9%diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (Lucirin® TPO isavailable from BASF Corporation, 100 Campus Drive, Florham Park, N.J.,USA) and 4.605% IRGACURE® 500 (from Ciba Specialty Chemicals 540 WhitePlains Road, Tarrytown, N.Y., U.S.A.). These components are thoroughlymixed by the helical mixer until a smooth composition is produced. Thiscomposition is applied by HVLP and cured by UV light.

Example 10 Procedure Used for Making Clear Hard Coatings With SlipProperties

A further embodiment is the procedure used for making a clear coat. Thecomponents of the coatings composition are mixed under air, as thepresence of oxygen prevents premature polymerization. It is desired thatexposure light be kept to a minimum, in particularly the use of sodiumvapor lights should be avoided. However, the use of darkroom lightingmay be an option. The components used in the manufacture of the coatingcomposition which come in contact with monomers and coating mixture,such as mixing vessels and mixing blades, should be made of stainlesssteel or plastic, preferably polyethylene or polypropylene. Polystyreneand PVC should be avoided, as the monomers and coating mixture willdissolve them. In addition, contact of the monomers and coating mixturewith mild steel, alloys of copper, acids, bases, and oxidizers should beavoided. Furthermore, brass fittings must be avoided, as they will causepremature polymerization or gelling. For the manufacture of clearcoatings it is only essential to obtain thorough mixing, andconsequently the control of shear is not necessary. Adequate mixing ofthe clear coating composition can be obtained after 1-3 hours using a ⅓horse power (hp) mixer and a 50 gallon cylindrical tank. Smallerquantities, up to 5 gallons, can be adequately mixed after 3 hours usinga laboratory mixer ( 1/15- 1/10 hp). Round walled vessels are desired asthis avoids accumulation of solid oligomer in corners and any subsequentproblems associated with incomplete mixing. Another, parameter is thatthe mixers blades should be placed off of the bottom of the mixingvessel, at a distance of one half of the diameter of the mixer. Theoligomers are added to the mixing vessel first, and if necessary theoligomers are gently warmed to aid in handling. Oligomers should not beheated over 120° F., therefore if warming is needed the use of atemperature controlled heating oven or heating mantle is recommended.Band heaters should be avoided. Monomers and colloidal suspensions areadded next, in any order, followed by the ester/monomer adhesionpromoters, corrosion inhibitors, nano-filler, and slip and flowenhancer. Photoinitiators are added last to ensure that the time thecomplete composition is exposed to light is minimized. With the mixingvessel shielded from light exposure the mixing is then carried out afterall the components are added. After mixing, there are air bubblespresent and the coating may appear cloudy. These bubbles rapidlydissipate, leaving a clear coating composition. As a final step, priorto removing the coating composition from the mixing vessel, the bottomof the mixing vessel is scraped to see if any un-dissolved oligomer ispresent. This is done as a precaution to ensure thorough mixing hastaken place. If the composition is thoroughly mixed then the coatingcomposition is filtered through a 1 micron filter using a bag filter.The composition is then ready for use.

Example 11 Manufacture Procedure for Making Pigmented Hard Coatings WithSlip Properties

A further embodiment is the manufacture procedure for pigmentedcoatings. Here a mixer of sufficient power and configuration is used tocreate laminar flow and efficiently bring the pigment dispersionsagainst the blades of the mixer. For small laboratory quantities below400 mLs, a laboratory mixer or blender is sufficient, however forquantities of up to half of a gallon a 1/15- 1/10 hp laboratory mixercan be used, but mixing will take several days. For commercialquantities, a helical or saw-tooth mixer of at least 30 hp with a 250gallon round walled, conical bottomed tank may be used. To make apigmented composition a clear coating composition is mixed first, seeExample 3. The pigment dispersion mixtures are premixed prior toaddition to the clear coat composition as this ensures obtaining thecorrect color. The premixing of the pigments dispersions is easilyachieved by shaking the pigments dispersion in a closed container, whilewearing a dust mask. The premixed pigments/pigment dispersions, andsolid photoinitiator are then added to the clear coat composition andmixed for 1½ to 2 hours. Completeness of mixing is determined byperforming a drawdown and checking for un-dissolved pigment. This isaccomplished by drawing off a small quantity of the pigmented mixturefrom the bottom of the mixing tank and applying a thin coating onto asurface. This thin coating is then examined for the presence of anypigment which had not dissolved. The mixture is then run through a 100mesh filter. A thoroughly mixed pigmented coating composition will showlittle or no un-dissolved pigment.

Example 12 Process for Coating the External Surface of Hydraulic RodsWith Clear Hard Coatings Having Slip Properties

Still another embodiment is the process for coating the external surfaceof hydraulic rods with an actinic radiation curable, substantially allsolids composition as described in example 1. The process begins byattaching a hydraulic rod to rotation system to allow rotation of theshaft around the axis running along the rod length, and then attachingthis combination to a conveyer belt system. The hydraulic rod may bepre-cleaned using a biodegradable organic cleaner at a separate CleaningStation or the hydraulic rod may be pre-cleaned prior to attachment ontothe rotation system. Note that rotation of the hydraulic rod assemblyduring the coating procedure ensures a complete coating of the hydraulicrod surface. The rotatable hydraulic rod assembly is then moved via theconveyer belt system into the coating application section, locating therotatable hydraulic rod assembly in the vicinity of electrostaticspraying system. The electrostatic spraying system has three spray headsarranged to ensure top, bottom and side coverage of the object beingcoated. Rotation of the hydraulic rod assembly begins prior to sprayingof the coating composition (described in Example 1) from the three sprayheads. The coating composition is then applied simultaneously from thethree electrostatic spray heads, while the hydraulic rod assemblycontinues to rotate. The coated hydraulic rod assembly is thentransported by the conveyer belt into a curing chamber located furtherdown the process line. The curing chamber has two sets of doors whichare closed during curing to protect operators form exposure to UVradiation. Inside the curing chamber the three sets of UV lamps arearranged to ensure top, bottom and side exposure to the UV radiation.Furthermore each UV lamp set contains two separate lamp types; one amercury arc lamp and the other a mercury arc lamp doped with iron, toensure proper curing. Therefore there are actually six lamps with in thecuring chamber. Note that this three dimensional curing can be achievedby using only two lamps, one a mercury arc lamp and the other a mercuryarc lamp doped with iron, with a mirror assembly to ensure exposure tothe top, bottom and sides. Once inside the curing chamber the doorsclose and the hydraulic rod assembly is again rotated. The mercury arclamp doped with iron is then activated for the partial curing stage, andthen the mercury arc lamp is activated for full cure. Note that themercury arc lamp doped with iron does not need to be completely offbefore the mercury arc lamp is turned on, and the time of exposure tothe doped mercury arc lamp is less than the time of exposure to the puremercury arc lamp. Both lamps are turned off and rotation of thehydraulic rod assembly is stopped. The doors on the other side of thecuring chamber are opened and the fully cured hydraulic rod with aclear, hard, abrasion and scratch resistant coating with slip propertiesis then moved via the conveyer belt to a packaging area away from thecuring chamber. The hydraulic rod is then removed from the rotationsystem, packed and shipped.

Example 13 Pencil Hardness Testing of Clear Hard Coatings Having SlipProperties

A further embodiment is testing the hardness of the UV-curable coatingdescribed in Example 1. The hardness of the cured composition coatedonto a test panel, was conducted using a pencil hardness test by pushingpencil leads of known hardness across the coated test panel. Gradingpencils from hard to soft, ranging in hardness from 9 H to 9 B, wereused. The coated test panel was placed on a firm horizontal surface andthe pencil, held at a 45° angle, was pushed away from in a ¼ inch (6.5mm) stroke. The process was started with the hardest pencil andcontinued down the scale of hardness to the point when a pencil did notcut into or gouge the coating. This gave the pencil hardness value of 7H for the UV-curable coating described in Example 1.

All percentages given are by weight. EBECRYLs® are available from UCBSurface Specialties, Brussels, Belgium. SYLOIDs® are available from theGrace Davison division of WR Grace & Co., Columbia, Md., U.S.A. Citedsolid pigment dispersions are available from Elementis, Staines, UK.IRGACURE® and DAROCUR® photoinitiators are available ® from CibaSpecialty Chemicals 540 White Plains Road, Tarrytown, N.Y., U.S.A. LANCOMATTE 2000® is available from Lubrizol, Wickliffe, Ohio U.S.A. CN386 andCN990 are available from Sartomer, Exton, Pa., U.S.A. ESACURE® KTO 46 isavailable from Lamberti S.p.A., Gallarate (VA), Italy. LUCIRIN® TPO isavailable from BASF Corporation, 100 Campus Drive, Florham Park, N.J.,USA. IRGANOX® from Ciba Specialty Chemicals 540 White Plains Road,Tarrytown, N.Y., U.S.A. Nano-alumina in tripropylene glycol diacrylate;Nanobyk™ 3601 is available from Nanophase Technologies Corporation 1319Marquette Drive, Romeoville, Ill.

While the invention has been described in connection with certainembodiments, it is not intended to limit the scope of the invention tothe particular form set forth, but on the contrary, it is intended tocover such alternatives, modifications, and equivalents as may beincluded within the spirit and scope of the invention as defined by theappended claims.

1. An actinic radiation curable, substantially all solids compositioncomprising a mixture of about 15-45% by weight of an oligomer or amultiplicity of oligomers; about 30-65% by weight of a monomer ormultiplicity of monomers; about 2-10% by weight of a photoinitiator or amultiplicity of photoinitiators; about 0.1-5% by weight of nano-alumina;and about 0.01-2% by weight of a corrosion inhibitor or a multiplicityof corrosion inhibitors; wherein the cured composition is a slick,abrasion and scratch resistant coating with at least 6 H hardness; andwherein thermal curing is not required to attain the at least 6 Hhardness.
 2. The actinic radiation curable, substantially all solidscomposition of claim 1, wherein the oligomer or a multiplicity ofoligomers comprises a slip and flow enhancing oligomer.
 3. The actinicradiation curable, substantially all solids composition of claim 1wherein the mixture further comprises up to about 15% by weight of apolymerizable pigment dispersion or a multiplicity of polymerizablepigment dispersions.
 4. The actinic radiation curable, substantially allsolids composition of claim 1, further comprising up to about 2% of aco-photoinitiator selected from a group consisting of an amine acrylate,thioxanthone, benzyl methyl ketal, and combinations thereof.
 5. Theactinic radiation curable, substantially all solids composition of claim1, wherein the corrosion inhibitor is M-235.
 6. The actinic radiationcurable, substantially all solids composition of claim 1 used as a hardchrome substitute.
 7. The actinic radiation curable, substantially allsolids composition of claim 1 used to coat an object, wherein the coatedportion of the object comprises metal, glass, or plastic.
 8. The actinicradiation curable, substantially all solids composition of claim 7wherein the object is selected from hydraulic rods, hydraulic cylinders,aircraft jet engine components, diesel cylinder liners, pneumatic strutsfor automobile hatchbacks, shock absorbers, aircraft landing gear,railroad wheel bearings, railroad wheel couplers, tool parts, die parts,plastic molds, rubber molds, and glass.
 9. The actinic radiationcurable, substantially all solids composition of claim 8 wherein theobject is hydraulic rods.
 10. The actinic radiation curable,substantially all solids composition of claim 1, wherein the monomer ormultiplicity of monomers is selected from a group consisting of atrimethylolpropane triacrylate, a 2-phenoxyethyl acrylate, an isobomylacrylate, a propoxylated glyceryl triacrylate, an acrylate esterderivative, a methacrylate ester derivative, a tripropylene glycoldiacrylate, an acrylate ester derivative and combinations thereof. 11.The actinic radiation curable, substantially all solids composition ofclaim 1, wherein the photoinitiator or multiplicity of photoinitiatorsis selected from a group consisting of diphenyl (2,4,6-trimethylbenzoyl)phosphine oxide, beuzophenone, 1-hydroxycyclohexyl phenyl ketone,2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2,4,6-trimethylbenzophenone,4-methylbenzophenone, oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone), andcombinations thereof.
 12. The actinic radiation curable, substantiallyall solids composition of claim 3, wherein the polymerizable pigmentdispersions are comprised of at least one pigment attached to anactivated resin.
 13. The actinic radiation curable, substantially allsolids composition of claim 12, wherein the activated resin is selectedfrom a group consisting of an acrylate resin, a methacrylate resin, anda vinyl resin.
 14. The actinic radiation curable, substantially allsolids composition of claim 12, wherein the pigment is selected from agroup consisting of carbon black, rutile titanium dioxide, organic redpigment, phthalo blue pigment, red oxide pigment, isoindoline yellowpigment, phthalo green pigment, quinacridone violet, carbazole violet,masstone black, light lemon yellow oxide, light organic yellow,transparent yellow oxide, diarylide orange, quinacridone red, organicscarlet, light organic red, and deep organic red.